This patch ensures that grub-probe will find the root device placed in
/dev/mapper/dm-[0-9]+-.* e.g. device named /dev/mapper/dm-0-luks will be
found and grub.cfg will be updated properly, enabling the system to boot.
Signed-off-by: Oleg Solovyov <mcpain@altlinux.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>