Code review comment for lp:~smoser/curtin/trunk.lp1716028-hack-file-locking-in-qemu

I notice now that
 cls.mpath_args(cls.mpath_diskargs(target_disks + extra_disks + nvme_disks)
is not really the same as waht we did before, which was effectively:
cls.mpath_diskargs(target_disks) + cls.mpath_diskargs(extra_disks) + cls.mpath_diskargs(nvme_disks)

the difference is really just in order, effectively
new: [a,b,c] * 2 = [a, b, c, a, b, c]
where before we had
 [a] * 2 + b * 2 + c * 2 = [a, a, b, b, c, c]

it all should really come out the same just different order of -drive options/-device options.