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/sco.c b/net/bluetooth/sco.c
index a92aeba..12a0e51 100644
--- a/net/bluetooth/sco.c
+++ b/net/bluetooth/sco.c
@@ -1177,15 +1177,14 @@
 		goto error;
 	}
 
-	if (bt_debugfs) {
-		sco_debugfs = debugfs_create_file("sco", 0444, bt_debugfs,
-						  NULL, &sco_debugfs_fops);
-		if (!sco_debugfs)
-			BT_ERR("Failed to create SCO debug file");
-	}
-
 	BT_INFO("SCO socket layer initialized");
 
+	if (IS_ERR_OR_NULL(bt_debugfs))
+		return 0;
+
+	sco_debugfs = debugfs_create_file("sco", 0444, bt_debugfs,
+					  NULL, &sco_debugfs_fops);
+
 	return 0;
 
 error: