tunable (until we get REPORT LUNS in place).
If we're probing luns, and each probe succeeds, we keep going past
lun 7 if we're a SCSI3 or better device (until we fail to probe).
If we're probing luns, and a probe fails, we only keep going if
we're quirked *for* it (CAM_QUIRK_HILUNS), and if we're not quirked
*against* it (CAM_QUIRK_NOHILUNS), or we're a SCSI3 or better device
and the tunable (kern.cam.cam_srch_hi) is set non-zero.
Reviewed by: nate@rootlabs.org, gibbs@scsiguy.com, ken@kdm.com, scottl@samsco.org
MFC after: 1 week
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