[SCSI] qla2xxx: Correct use-after-free oops seen during EH-abort.

Hold a reference to the srb (sp) while aborting an I/O -- as the
I/O can/will complete from within the interrupt-context.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: Giridhar Malavali <giridhar.malavali@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 8396109..f8239bf 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -202,6 +202,7 @@
  * SCSI Request Block
  */
 typedef struct srb {
+	atomic_t ref_count;
 	struct fc_port *fcport;
 	uint32_t handle;