recipe: Fix virt-who call

The condition around the virt-who fix sometimes does not evaluate to
true, if the file is created after the virt-who snippet.

Change-Id: Iafa3787ccc7d817c8183ceb3b8450605bfa963df
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1152414
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1158497
Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>