Revert "[fuse] fix deadlock between fuse_put_super() and request_end()"
This reverts 73ce8355 commit. It was wrong, because it didn't take into account the requirement, that iput() for background requests must be performed synchronously with ->put_super(), otherwise active inodes may remain after unmount. The right solution is to keep the sbput_sem and perform iput() within the locked region, but move fput() outside sbput_sem. Signed-off-by: Miklos Szeredi <email@example.com>