MFC: r218811:

MFC: r218811:

In the MPS driver, during device removal processing, don't assume that
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

git-svn-id: svn://svn.freebsd.org/base/stable/8@218921 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f