shmem: rename functions that are memfd-related

Those functions are called for memfd files, backed by shmem or hugetlb
(the next patches will handle hugetlb).

Link: http://lkml.kernel.org/r/20171107122800.25517-3-marcandre.lureau@redhat.com
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fcntl.c b/fs/fcntl.c
index c7b9e09..e95fa0a 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -418,7 +418,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg,
 		break;
 	case F_ADD_SEALS:
 	case F_GET_SEALS:
-		err = shmem_fcntl(filp, cmd, arg);
+		err = memfd_fcntl(filp, cmd, arg);
 		break;
 	case F_GET_RW_HINT:
 	case F_SET_RW_HINT: