libcacard/vcard_emul_nss: Drop a redundant conditional

Bailing out when PK11_FindGenericObjects() returns null ensures the
loop that follows it executes at least once.  The "loop did not
execute" test right after it is useless.  Drop it.

Spotted by Coverity.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alon Levy <alevy@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>