i2c: mux: only print failure message on error

As is, a failure message is printed unconditionally, which is confusing.
And noisy.

Fixes: 8d4d159f ("i2c: mux: provide more info on failure in i2c_mux_add_adapter")
Signed-off-by: Peter Rosin <peda@axentia.se>

drivers/i2c/i2c-mux.c

@@ -395,18 +395,20 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
 	if (force_nr) {
 		priv->adap.nr = force_nr;
 		ret = i2c_add_numbered_adapter(&priv->adap);
+		if (ret < 0) {
 			dev_err(&parent->dev,
 				"failed to add mux-adapter %u as bus %u (error=%d)\n",
 				chan_id, force_nr, ret);
+			goto err_free_priv;
+		}
 	} else {
 		ret = i2c_add_adapter(&priv->adap);
+		if (ret < 0) {
 			dev_err(&parent->dev,
 				"failed to add mux-adapter %u (error=%d)\n",
 				chan_id, ret);
+			goto err_free_priv;
 		}
-	if (ret < 0) {
-		kfree(priv);
-		return ret;
 	}
 
 	WARN(sysfs_create_link(&priv->adap.dev.kobj, &muxc->dev->kobj,
@@ -422,6 +424,10 @@ int i2c_mux_add_adapter(struct i2c_mux_core *muxc,
 
 	muxc->adapter[muxc->num_adapters++] = &priv->adap;
 	return 0;
+
+err_free_priv:
+	kfree(priv);
+	return ret;
 }
 EXPORT_SYMBOL_GPL(i2c_mux_add_adapter);