Description of problem:
After update to the latest build via "yum update", also can update to itself via "yum install *update*.rpm".
Should not permit update to itself after update to the latest build.

Version-Release number of selected component (if applicable):
1. Before update:
RHVH-7.2-20160718.1-RHVH-x86_64-dvd1.iso
redhat-virtualization-host-image-update-placeholder-4.0-0.20.el7.noarch
imgbased-0.7.2-0.1.el7ev.noarch
kernel-3.10.0-327.22.2.el7.x86_64
2. After update:
redhat-virtualization-host-4.0-20160714.5
redhat-virtualization-host-image-update-placeholder-4.0-0.20.el7.noarch
imgbased-0.7.2-0.1.el7ev.noarch
kernel-3.10.0-327.22.2.el7.x86_64


How reproducible:
100%


Steps to Reproduce:
1. Install RHVH-7.2-20160718.1-RHVH-x86_64-dvd1.iso
2. Reboot and login RHVH, register to RHSM and enable repos
   # imgbase layout
     rhvh-4.0-0.20160714.3
     +- rhvh-4.0-0.20160714.3+1
   # imgbase w
     [INFO] You are on rhvh-4.0-0.20160714.3+1
3. Update via "yum update"
   #yum update
4. Reboot and login new build: redhat-virtualization-host-4.0-20160714.5
   # imgbase layout
     rhvh-4.0-0.20160714.3
     +- rhvh-4.0-0.20160714.3+1
     rhvh-4.0-0.20160714.5
     +- rhvh-4.0-0.20160714.5+1
   # imgbase w
     [INFO] You are on rhvh-4.0-0.20160714.5+1
5. Load redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch.rpm and update again:
   # yum install redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch.rpm



Actual results:
1. After step5, it can access update process and can update to itself:
# yum install redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch.rpm
Loaded plugins: imgbased-warning, product-id, search-disabled-repos, subscription-manager
Warning: yum operations are not persisted across upgrades!
Examining redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch.rpm: redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch
Marking redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package redhat-virtualization-host-image-update.noarch 0:4.0-20160714.5.el7 will be obsoleting
---> Package redhat-virtualization-host-image-update-placeholder.noarch 0:4.0-0.20.el7 will be obsoleted
--> Finished Dependency Resolution

Dependencies Resolved

==================================================================================================================================================
 Package                                  Arch    Version               Repository                                                           Size
==================================================================================================================================================
Installing:
 redhat-virtualization-host-image-update  noarch  4.0-20160714.5.el7    /redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch  481 M
     replacing  redhat-virtualization-host-image-update-placeholder.noarch 4.0-0.20.el7

Transaction Summary
==================================================================================================================================================
Install  1 Package

Total size: 481 M
Is this ok [y/d/N]: y
Downloading packages:
Running transaction check
Running transaction test
Transaction test succeeded
Running transaction
Warning: RPMDB altered outside of yum.
  Installing : redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch                                                              1/2
warning: %post(redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch) scriptlet failed, exit status 1
Non-fatal POSTIN scriptlet failure in rpm package redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch
  Erasing    : redhat-virtualization-host-image-update-placeholder-4.0-0.20.el7.noarch                                                        2/2
  Verifying  : redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch                                                              1/2
  Verifying  : redhat-virtualization-host-image-update-placeholder-4.0-0.20.el7.noarch                                                        2/2

Installed:
  redhat-virtualization-host-image-update.noarch 0:4.0-20160714.5.el7                                                                            

Replaced:
  redhat-virtualization-host-image-update-placeholder.noarch 0:4.0-0.20.el7                                                                      

Complete!


Expected results:
1. After step5, should not update to itself, and can give warning message, such as:

Loaded plugins: imgbased-warning, product-id, search-disabled-repos, subscription-manager
Warning: yum operations are not persisted across upgrades!
Examining redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch.rpm: redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch
redhat-virtualization-host-image-update-4.0-20160714.5.el7.noarch.rpm: does not update installed package.
Error: Nothing to do


Additional info: 
After step5, can not update via "yum update", it will report like below:
# yum update
Loaded plugins: imgbased-warning, product-id, search-disabled-repos, subscription-manager
Warning: yum operations are not persisted across upgrades!
No packages marked for update