scsi: mptsas: remove duplicated assignment to pointer head

The pointer head is re-assigned the same value twice, so remove the
second redundant assignment.

Cleans up clang warning:
drivers/message/fusion/mptsas.c:1161:20: warning: Value stored to 'head'
during its initialization is never read
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>

drivers/message/fusion/mptsas.c

@@ -1165,7 +1165,6 @@ mptsas_schedule_target_reset(void *iocp)
 	 * issue target reset to next device in the queue
 	 */
 
-	head = &hd->target_reset_list;
 	if (list_empty(head))
 		return;