inode: make i_state a u32

Now that we use the wait var event mechanism make i_state a u32 and free
up 4 bytes. This means we currently have two 4 byte holes in struct
inode which we can pack.

Link: https://lore.kernel.org/r/20240823-work-i_state-v3-6-5cd5fd207a57@kernel.org


Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>