[SCSI] scsi_dh_alua: fix submit_stpg return

submit_stpg() will always return failure so alua_activate() will report
failure via dm-multipath callback function.  Even though the stpg fired
successfuly dm-multipath does not know and always fails to change the
valid path.

By returning SCSI_DH_OK we're now skipping alua_activate()'s call to
activate_complete 'fn'.  But this is fine because stpg_endio() will call
it via h->callback_fn().
Signed-off-by: Joseph Gruher <joseph.r.gruher@intel.com>
Signed-off-by: Ilgu Hong <ilgu.hong@promise.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/device_handler/scsi_dh_alua.c

@@ -303,7 +303,6 @@ static void stpg_endio(struct request *req, int error)
 static unsigned submit_stpg(struct alua_dh_data *h)
 {
 	struct request *rq;
-	int err = SCSI_DH_RES_TEMP_UNAVAIL;
 	int stpg_len = 8;
 	struct scsi_device *sdev = h->sdev;
 
@@ -332,7 +331,7 @@ static unsigned submit_stpg(struct alua_dh_data *h)
 	rq->end_io_data = h;
 
 	blk_execute_rq_nowait(rq->q, NULL, rq, 1, stpg_endio);
-	return err;
+	return SCSI_DH_OK;
 }
 
 /*