btrfs: sink iterator parameter to btrfs_ioctl_logical_to_ino

[ Upstream commit e3059ec0 ]

There's only one function we pass to iterate_inodes_from_logical as
iterator, so we can drop the indirection and call it directly, after
moving the function to backref.c

Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 418ffb9e ("btrfs: free btrfs_path before copying inodes to userspace")
Signed-off-by: Sasha Levin <sashal@kernel.org>