crypto: api - Change crypto_unregister_instance argument type

This patch makes crypto_unregister_instance take a crypto_instance
instead of a crypto_alg.  This allows us to remove a duplicate
CRYPTO_ALG_INSTANCE check in crypto_unregister_instance.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --cc crypto/algapi.c
Simple merge

diff --cc crypto/crypto_user.c
Simple merge

diff --cc include/crypto/algapi.h
Simple merge