libcacard/vreader: Tighten assertion to clarify intent
libcacard/vreader: Tighten assertion to clarify intent

Bonus: hushes up Coverity.

Signed-off-by: Markus Armbruster <5d00b6b660f20fb41305186c34c40973ec5cb35b@redhat.com>
Reviewed-by: Alon Levy <816c907b754fa7b5d4bb5eb91e0fc01e5510e64d@redhat.com>
Signed-off-by: Michael Tokarev <389bd06664b699d49ce291f515b98373073ad5f4@tls.msk.ru>

elmarco/libcacard,elmarco/libcacard,SPICE/libcacard,SPICE/libcacard