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>