[SCSI] csiostor: remove unused variable in csio_process_fwevtq_entry()

The variable 'data' is initialized but never used
otherwise, so remove the unused variable.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Acked-by: Naresh Kumar Inna <naresh@chelsio.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>