btrfs: add a test case for the logical to ino ioctl

btrfs: add a test case for the logical to ino ioctl

Add a test case to exercise the logical to ino ioctl, including the v2
version (which adds the ignore offset option). This is motivated by the
fact that we have no test cases giving full coverage to that ioctl, only
two test cases partially exercise it (btrfs/004 and btrfs/299) and
absolutely no coverage for the v2 ioctl. This resulted in a recent
regression fixed by the patch mentioned in the _fixed_by_kernel_commit
tag of the introduced test case.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>