xen-netback: no need to check return value of debugfs_create functions

When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Cc: Wei Liu <wei.liu@kernel.org>
Cc: Paul Durrant <paul.durrant@citrix.com>
Cc: xen-devel@lists.xenproject.org
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/xen-netback/netback.c

@@ -1653,9 +1653,6 @@ static int __init netback_init(void)
 
 #ifdef CONFIG_DEBUG_FS
 	xen_netback_dbg_root = debugfs_create_dir("xen-netback", NULL);
-	if (IS_ERR_OR_NULL(xen_netback_dbg_root))
-		pr_warn("Init of debugfs returned %ld!\n",
-			PTR_ERR(xen_netback_dbg_root));
 #endif /* CONFIG_DEBUG_FS */
 
 	return 0;

drivers/net/xen-netback/xenbus.c

@@ -170,50 +170,26 @@ DEFINE_SHOW_ATTRIBUTE(xenvif_ctrl);
 
 static void xenvif_debugfs_addif(struct xenvif *vif)
 {
-	struct dentry *pfile;
 	int i;
 
-	if (IS_ERR_OR_NULL(xen_netback_dbg_root))
-		return;
-
 	vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
 						  xen_netback_dbg_root);
-	if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
+	for (i = 0; i < vif->num_queues; ++i) {
-		for (i = 0; i < vif->num_queues; ++i) {
+		char filename[sizeof("io_ring_q") + 4];
-			char filename[sizeof("io_ring_q") + 4];
 
-			snprintf(filename, sizeof(filename), "io_ring_q%d", i);
+		snprintf(filename, sizeof(filename), "io_ring_q%d", i);
-			pfile = debugfs_create_file(filename,
+		debugfs_create_file(filename, 0600, vif->xenvif_dbg_root,
-						    0600,
+				    &vif->queues[i],
-						    vif->xenvif_dbg_root,
+				    &xenvif_dbg_io_ring_ops_fops);
-						    &vif->queues[i],
+	}
-						    &xenvif_dbg_io_ring_ops_fops);
-			if (IS_ERR_OR_NULL(pfile))
-				pr_warn("Creation of io_ring file returned %ld!\n",
-					PTR_ERR(pfile));
-		}
 
-		if (vif->ctrl_irq) {
+	if (vif->ctrl_irq)
-			pfile = debugfs_create_file("ctrl",
+		debugfs_create_file("ctrl", 0400, vif->xenvif_dbg_root, vif,
-						    0400,
+				    &xenvif_ctrl_fops);
-						    vif->xenvif_dbg_root,
-						    vif,
-						    &xenvif_ctrl_fops);
-			if (IS_ERR_OR_NULL(pfile))
-				pr_warn("Creation of ctrl file returned %ld!\n",
-					PTR_ERR(pfile));
-		}
-	} else
-		netdev_warn(vif->dev,
-			    "Creation of vif debugfs dir returned %ld!\n",
-			    PTR_ERR(vif->xenvif_dbg_root));
 }
 
 static void xenvif_debugfs_delif(struct xenvif *vif)
 {
-	if (IS_ERR_OR_NULL(xen_netback_dbg_root))
-		return;
-
 	debugfs_remove_recursive(vif->xenvif_dbg_root);
 	vif->xenvif_dbg_root = NULL;
 }