Bug 1261593

Description of problem:
I was verifying bz1187648 and while selecting disks, its exiting with this error.

Version-Release number of selected component:
anaconda-21.48.22.41-1

The following was filed automatically by anaconda:
anaconda 21.48.22.41-1 exception report
Traceback (most recent call first):
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 274, in empty_device
    empty = all([p.isMagic for p in partitions])
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 755, in shouldClear
    if not empty_device(device, self.devicetree):
  File "/usr/lib/python2.7/site-packages/blivet/__init__.py", line 962, in getFreeSpace
    clearPartDisks=[disk.name])
  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/gui/spokes/storage.py", line 613, in _update_summary
    free_space = self.storage.getFreeSpace(disks=self.disks)
  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/gui/spokes/storage.py", line 520, in refresh
    self._update_summary()
  File "/usr/lib64/python2.7/site-packages/pyanaconda/ui/gui/hubs/__init__.py", line 355, in _on_spoke_clicked
    spoke.refresh()
AttributeError: 'MultipathDevice' object has no attribute 'isMagic'

Additional info:
addons:         com_redhat_kdump, org_fedora_oscap
cmdline:        /usr/bin/python  /sbin/anaconda
cmdline_file:   initrd=/images/storageqe-84.lab.eng.brq.redhat.com/initrd console=ttyS1,115200n81 ks=http://beaker.engineering.redhat.com/kickstart/1551831 ksdevice=bootif serial vnc netboot_method=pxe BOOT_IMAGE=/images/storageqe-84.lab.eng.brq.redhat.com/kernel BOOTIF=01-a0-d3-c1-02-1c-c8 
executable:     /sbin/anaconda
hashmarkername: anaconda
kernel:         3.10.0-313.el7.x86_64
product:        Red Hat Enterprise Linux 7
release:        Red Hat Enterprise Linux Workstation release 7.2 Beta (Maipo)
release_type:   pre-release
type:           anaconda
uid:            0
version:        7.2