according to my reading of the CAM draft is mandatory for
all CCB function calls and enforced by xptioctl() since at
least r168752. Previously we happened to use 0 as the Path
ID, causing the XPT_DEV_MATCH call to fail if there's no
SCSI bus 0. Basically the same bug was also fixed the same
way for camcontrol(8) as part of r126514.
PR: 127605
Submitted by: Eygene Ryabinkin
Approved by: silence from ken and scottl
MFC after: 1 week
25ea4c843f