nvme-loadgen does not handle drives that aren't formatted

[rmustacc]

The implementation of the nvme-loadgen logic requires that a pool exists. When the p0 minor doesn't exist, because say the drive came from the factory and never had anything on it, it'll fail. I manually just created a zpool and then destroyed it to get the right whole disk partitioning. We should consider doing something like this. The error when this fails looks something like:

[ Dec 28 04:17:21 Executing start method ("/usr/lib/compliance-nvme-loadgen seqread N0"). ]
[ Dec 28 04:17:34 Method "start" exited with status 0. ]
Starting 1 process
fio: failed opening chardev /dev/rdsk/c9t0014EE8401CE2900d0p0 for size check
file:filesetup.c:795, func=open(/dev/rdsk/c9t0014EE8401CE2900d0p0), error=No such device or address
fio: pid=0, err=6/file:filesetup.c:795, func=open(/dev/rdsk/c9t0014EE8401CE2900d0p0), error=No such device or address


Run status group 0 (all jobs):
[ Dec 28 04:17:34 Stopping because all processes in service exited. ]
[ Dec 28 04:17:34 Executing stop method (:kill). ]

[dancrossnyc]

Probably the easiest fix here is for the loadgen script to test for the minor and do fdisk -E if it doesn't exist.