staging: ks7010: remove redundant auth_type check

The range check on auth_type is redundant as there is a prior
check on the auth_type values and the only way the block is entered
is if auth_type is one of TYPE_PMK1, TYPE_GMK1 and TYPE_GMK2. Hence
the auth_type check can be removed.

Detected by static analysis with cppcheck.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>