ionic: only save good lif dentry

Don't save the lif->dentry until we know we have
a good value.

Fixes: 1a58e19 ("ionic: Add basic lif support")
Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/pensando/ionic/ionic_debugfs.c

@@ -228,7 +228,13 @@ DEFINE_SHOW_ATTRIBUTE(netdev);
 
 void ionic_debugfs_add_lif(struct ionic_lif *lif)
 {
-	lif->dentry = debugfs_create_dir(lif->name, lif->ionic->dentry);
+	struct dentry *lif_dentry;
+
+	lif_dentry = debugfs_create_dir(lif->name, lif->ionic->dentry);
+	if (IS_ERR_OR_NULL(lif_dentry))
+		return;
+	lif->dentry = lif_dentry;
+
 	debugfs_create_file("netdev", 0400, lif->dentry,
 			    lif->netdev, &netdev_fops);
 }