new helper: memcpy_to_msg()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/crypto/algif_hash.c b/crypto/algif_hash.c
index 8502462..35c93ff 100644
--- a/crypto/algif_hash.c
+++ b/crypto/algif_hash.c
@@ -174,7 +174,7 @@
 			goto unlock;
 	}
 
-	err = memcpy_toiovec(msg->msg_iov, ctx->result, len);
+	err = memcpy_to_msg(msg, ctx->result, len);
 
 unlock:
 	release_sock(sk);