ext4: Remove ext4 locking of moved directory

Remove locking of moved directory in ext4_rename2(). We will take care
of it in VFS instead. This effectively reverts commit 0813299c


("ext4: Fix possible corruption when moving a directory") and followup
fixes.

CC: Ted Tso <tytso@mit.edu>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Message-Id: <20230601105830.13168-1-jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>