crypto: api - fixed style erro in algapi.c

Fixed style error identified by checkpatch.

WARNING: Missing a blank line after declarations
+               int err = crypto_remove_alg(&inst->alg, &users);
+               BUG_ON(err);

Signed-off-by: Joshua I. James <joshua@cybercrimetech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>