libcacard: Fix wrong assertion (reported by cppcheck)
libcacard: Fix wrong assertion (reported by cppcheck)

assert("...") will never do anything. This assertion handles a case
which should never occur, so it must be assert(!"...").

Cc: Alon Levy <816c907b754fa7b5d4bb5eb91e0fc01e5510e64d@redhat.com>
Signed-off-by: Stefan Weil <8d4c780fcfdc41841e5070f4c43da8958ba6aec0@weilnetz.de>

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