Description of problem:
The guest name is rhel7.1 instead of rhel7.2 when installing a guest with a rhel7.2 tree.

Version-Release number of selected component (if applicable):
virt-manager-1.2.1-6.el7.noarch
libosinfo-0.2.12-3.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Launch virt-manager and Select "Network Install(HTTP, FTP, or NFS)".
2. In Step2 of 5, type a rhel7.2 url(http://download.englab.nay.redhat.com/pub/rhel/rel-eng/RHEL-7.2-20150904.0/compose/Server/x86_64/os), and it automatically detect the version is rhel7.2. 
3. Click Foward until step 5 of 5, check the Name.

Actual results:
The guest name is rhel7.1-2.

Expected results:
The guest name should be rhel7.2 or rhel7.2-x (if guest rhel7.2 already exists).


Additional info:
1. the output of "osinfo-query os" is as below, i think it should be rhel7.2 for the 3rd line.

 rhel6.6              | Red Hat Enterprise Linux 6.6                       | 6.6      | http://redhat.com/rhel/6.6              
 rhel7.0              | Red Hat Enterprise Linux 7.0                       | 7.0      | http://redhat.com/rhel/7.0              
 rhel7.1              | Red Hat Enterprise Linux 7.2                       | 7.2      | http://redhat.com/rhel/7.2              
 rhel7.1              | Red Hat Enterprise Linux 7.1                       | 7.1      | http://redhat.com/rhel/7.1   

2. Can't find rhel6.7 info by "osinfo-query os".