fs: drop the lock trip around I_NEW wake up in evict()

The unhashed state check in __wait_on_freeing_inode() performed with
->i_lock held against remove_hash_inode() also holding the lock makes
another lock acquire in evict() completely spurious -- all potential
sleepers already dropped the lock before remove_hash_inode() acquired
it or they found the inode to be unhashed and aborted.

Note there is no trickery here: the usual cost of both sides taking
locks is still being paid, it just stops being paid twice.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250317160707.1694135-1-mjguzik@gmail.com


Signed-off-by: Christian Brauner <brauner@kernel.org>