[SCSI] mpt fusion: clear list of outstanding commands on host reset

A bug in the fusion driver was exposed by the switch to block timeout.
Basically, drivers are supposed to terminate commands once error
handling begins on them.  The fusion apparently wasn't doing this.
Under the old timeout regime, completions on terminated commands would
by and large get ignored because of the way command timeouts used to
work. The new block timers are very intolerant to this, though,
becuase the request gets cleaned and freed.

Fixes: http://bugzilla.kernel.org/show_bug.cgi?id=12195

Reported-by: Alex Shi <alex.shi@intel.com>
Tested-by: Ming Lin <ming.m.lin@intel.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>