Bluetooth: Use IS_ERR_OR_NULL for checking bt_debugfs

Make sure to use IS_ERR_OR_NULL for checking the existing of the root
debugfs dentry bt_debugfs.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index df17276..c4d3d42 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -1051,15 +1051,15 @@
 		goto error;
 	}
 
-	if (bt_debugfs) {
-		rfcomm_sock_debugfs = debugfs_create_file("rfcomm", 0444,
-				bt_debugfs, NULL, &rfcomm_sock_debugfs_fops);
-		if (!rfcomm_sock_debugfs)
-			BT_ERR("Failed to create RFCOMM debug file");
-	}
-
 	BT_INFO("RFCOMM socket layer initialized");
 
+	if (IS_ERR_OR_NULL(bt_debugfs))
+		return 0;
+
+	rfcomm_sock_debugfs = debugfs_create_file("rfcomm", 0444,
+						  bt_debugfs, NULL,
+						  &rfcomm_sock_debugfs_fops);
+
 	return 0;
 
 error: