crypto: user - Fix rwsem leak in crypto_user

The list_empty case in crypto_alg_match() will return without calling
up_read() on crypto_alg_sem.  We could do the "goto out" routine, but the
function will clearly do the right thing with that test simply removed.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>