[SCSI] qla4xxx: unblock iscsi session after setting ddb state online.

Once the device goes *missing*, driver blocks the session
ie iscsi_block_session() to stall the I/O.  So after device
comes back *online*, driver needs to unblock the session ie
iscsi_unblock_session(), else I/Os will fail even if
ddb_state is ONLINE.
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: Ravi Anand <ravi.anand@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

drivers/scsi/qla4xxx/ql4_init.c

@@ -993,6 +993,7 @@ int qla4xxx_reinitialize_ddb_list(struct scsi_qla_host *ha)
 			DEBUG2(printk ("scsi%ld: %s: ddb index [%d] marked "
 				       "ONLINE\n", ha->host_no, __func__,
 				       ddb_entry->fw_ddb_index));
+			iscsi_unblock_session(ddb_entry->sess);
 		} else if (atomic_read(&ddb_entry->state) == DDB_STATE_ONLINE)
 			qla4xxx_mark_device_missing(ha, ddb_entry);
 	}