journalctl: make "journalctl /dev/sda" work

journalctl: make "journalctl /dev/sda" work

Currently when journalctl is called with path to block device node we
add following match _KERNEL_DEVICE=b$MAJOR:$MINOR.

That is not sufficient to actually obtain logs about the disk because
dev_printk() kernel helper puts to /dev/kmsg information about the
device in following format, +$SUBSYSTEM:$ADDRESS,
e.g. "+pci:pci:0000:00:14.0".

Now we will walk upward the syspath and add match for every device in
format produced by dev_printk() as well as match for its device node if
it exists.