the controller firmware will return all of our commands. Instead, keep
track of outstanding I/Os and return them to CAM once device removal
processing completes.
mpsvar.h: Declare the new "io_list" in the mps_softc.
mps.c: Initialize the new "io_list" in the mps softc.
mps_sas.c: o Track SCSI I/O requests on the io_list from the
time of mpssas_action() through mpssas_scsiio_complete().
o Zero out the request structures used for device
removal commands prior to filling them out.
o Once the target reset task management function completes
during device removal processing, assume any SCSI I/O
commands that are still oustanding will never return
from the controller, and process them manually.
Submitted by: gibbs
MFC after: 3 days
9866848a62