pinctrl: mt7622: fix error path on failing at groups building

It should be to return an error code when failing at groups building.

Cc: stable@vger.kernel.org
Fixes: d6ed9355 ("pinctrl: mediatek: add pinctrl driver for MT7622 SoC")
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/mediatek/pinctrl-mt7622.c

@@ -1703,7 +1703,7 @@ static int mtk_pinctrl_probe(struct platform_device *pdev)
 	err = mtk_build_groups(hw);
 	if (err) {
 		dev_err(&pdev->dev, "Failed to build groups\n");
-		return 0;
+		return err;
 	}
 
 	/* Setup functions descriptions per SoC types */