[SCSI] mptfusion: task abort fix's

Fix's to insure proper status is returned to midlayer
when a task abort failed to be aborted by controller
firmware.

Also sanity checks to prevent scsi cmd from being
double completed during error recovery.

Signed-off-by: Eric Moore <Eric.Moore@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>