lsblk: use devno to get mountpoint

The device (for example LVM logical volume) could be renamed and then
the device name from /proc/self/mountinfo does not match with reality.
So, we also need to check devno. Unfortunately we cannot completely
rely on devno, because for example btrfs uses psudo device numbers.

References: https://bugzilla.redhat.com/show_bug.cgi?id=980463
Signed-off-by: Karel Zak <kzak@redhat.com>
lsblk: use devno to check if the filesystem is mounted

The device (for example LVM logical volume) could be renamed and then
the device name from /proc/self/mountinfo does not match with reality.
So, we also need to check devno. Unfortunately we cannot completely
rely on devno, because for example btrfs uses psudo device numbers.

References: https://bugzilla.redhat.com/show_bug.cgi?id=980463
Signed-off-by: Karel Zak <kzak@redhat.com>