jfs: move jfs_xattr_handlers to .rodata

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

Cc: Dave Kleikamp <shaggy@kernel.org>
Cc: jfs-discussion@lists.sourceforge.net
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Link: https://lore.kernel.org/r/20230930050033.41174-17-wedsonaf@gmail.com


Reviewed-by: Dave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>