scsi: qla1280: Remove set but not used variable in qla1280_mailbox_command()

This addresses the following gcc warning with "make W=1":

drivers/scsi/qla1280.c: In function ‘qla1280_mailbox_command’:
drivers/scsi/qla1280.c:2430:11: warning: variable ‘data’ set but not
used [-Wunused-but-set-variable]
 2430 |  uint16_t data;
      |           ^~~~

Link: https://lore.kernel.org/r/20200907074518.2326360-4-yanaijie@huawei.comReported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/qla1280.c

@@ -2425,7 +2425,6 @@ qla1280_mailbox_command(struct scsi_qla_host *ha, uint8_t mr, uint16_t *mb)
 	int cnt;
 	uint16_t *optr, *iptr;
 	uint16_t __iomem *mptr;
-	uint16_t data;
 	DECLARE_COMPLETION_ONSTACK(wait);
 
 	ENTER("qla1280_mailbox_command");
@@ -2460,7 +2459,7 @@ qla1280_mailbox_command(struct scsi_qla_host *ha, uint8_t mr, uint16_t *mb)
 
 	spin_unlock_irq(ha->host->host_lock);
 	WRT_REG_WORD(&reg->host_cmd, HC_SET_HOST_INT);
-	data = qla1280_debounce_register(&reg->istatus);
+	qla1280_debounce_register(&reg->istatus);
 
 	wait_for_completion(&wait);
 	del_timer_sync(&ha->mailbox_timer);