scsi: libiscsi: Move ehwait initialization to iscsi_session_setup()

Commit ec29d0ac29 ("scsi: iscsi: Fix conn use after free during resets")
moved member ehwait from 'conn' to 'session', but left the initialization
of ehwait in iscsi_conn_setup().

Although a session can only have 1 conn currently, it is better to
initialize ehwait in iscsi_session_setup() in case we implement handling
multiple conns in the future.

Link: https://lore.kernel.org/r/20210911135159.20543-1-dinghui@sangfor.com.cn
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: Ding Hui <dinghui@sangfor.com.cn>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/libiscsi.c

@@ -2947,6 +2947,7 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost,
 	session->tmf_state = TMF_INITIAL;
 	timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0);
 	mutex_init(&session->eh_mutex);
+	init_waitqueue_head(&session->ehwait);
 
 	spin_lock_init(&session->frwd_lock);
 	spin_lock_init(&session->back_lock);
@@ -3074,8 +3075,6 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size,
 		goto login_task_data_alloc_fail;
 	conn->login_task->data = conn->data = data;
 
-	init_waitqueue_head(&session->ehwait);
-
 	return cls_conn;
 
 login_task_data_alloc_fail: