shmem: move shmem_xattr_handlers to .rodata

This makes it harder for accidental or malicious changes to
shmem_xattr_handlers at runtime.

Cc: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mm@kvack.org
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230930050033.41174-29-wedsonaf@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: wedsonaf

mm/shmem.c

@@ -3714,7 +3714,7 @@ static const struct xattr_handler shmem_user_xattr_handler = {
 	.set = shmem_xattr_handler_set,
 };
 
-static const struct xattr_handler *shmem_xattr_handlers[] = {
+static const struct xattr_handler * const shmem_xattr_handlers[] = {
 	&shmem_security_xattr_handler,
 	&shmem_trusted_xattr_handler,
 	&shmem_user_xattr_handler,