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 --git a/include/crypto/algapi.h b/include/crypto/algapi.h
index 623a59c..0ecb768 100644
--- a/include/crypto/algapi.h
+++ b/include/crypto/algapi.h
@@ -137,7 +137,7 @@
 
 int crypto_register_instance(struct crypto_template *tmpl,
 			     struct crypto_instance *inst);
-int crypto_unregister_instance(struct crypto_alg *alg);
+int crypto_unregister_instance(struct crypto_instance *inst);
 
 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
 		      struct crypto_instance *inst, u32 mask);