scsi: ibmvscsis: Properly deregister target sessions

The driver currently doesn't properly deregisters target sessions
completely, so this will address that.

Signed-off-by: Bryant G. Ly <bryantly@linux.vnet.ibm.com>
Signed-off-by: Michael Cyr <mikecyr@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c
index 7e873a7..4cf37d4 100644
--- a/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c
+++ b/drivers/scsi/ibmvscsi_tgt/ibmvscsi_tgt.c
@@ -1934,6 +1934,8 @@
 	/*
 	 * Release the SCSI I_T Nexus to the emulated ibmvscsis Target Port
 	 */
+	target_wait_for_sess_cmds(se_sess);
+	transport_deregister_session_configfs(se_sess);
 	transport_deregister_session(se_sess);
 	tport->ibmv_nexus = NULL;
 	kfree(nexus);