sh-pfc: Fix return value check in sh_pfc_register_pinctrl()

In case of error, the function pinctrl_register() returns NULL not
ERR_PTR(). The IS_ERR() test in the return value check should be
replaced with NULL test.
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sh-pfc/pinctrl.c

@@ -395,8 +395,8 @@ int sh_pfc_register_pinctrl(struct sh_pfc *pfc)
 	pmx->pctl_desc.npins = pfc->info->nr_pins;
 
 	pmx->pctl = pinctrl_register(&pmx->pctl_desc, pfc->dev, pmx);
-	if (IS_ERR(pmx->pctl))
-		return PTR_ERR(pmx->pctl);
+	if (pmx->pctl == NULL)
+		return -EINVAL;
 
 	return 0;
 }