Fix checks for existence of vars set by fc-match

Fix checks for existence of vars set by fc-match

The first line here checked for the wrong variable and is a dupe
from two lines earlier anyway, and the second line isn't guarded
at all, which seems to cause the weird failure we've been seeing
in openQA testing.

Also add a couple more existence checks for the same variables
later.

Signed-off-by: Adam Williamson <awilliam@redhat.com>