scsi: qla2xxx: Make qla2x00_abort_srb() again decrease the sp reference count

Since qla2x00_abort_srb() starts with increasing the reference count of
@sp, decrease that same reference count before returning.

Cc: Himanshu Madhani <hmadhani@marvell.com>
Fixes: 219d27d7

 ("scsi: qla2xxx: Fix race conditions in the code for aborting SCSI commands") # v5.2.
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Tested-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Himanshu Madhani <hmadhani@marvell.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>