phy: rockchip: Fix return value of inno_dsidphy_probe()

When call function devm_platform_ioremap_resource(), we should use IS_ERR()
to check the return value and return PTR_ERR() if failed.

Fixes: b7535a3b ("phy/rockchip: Add support for Innosilicon MIPI/LVDS/TTL PHY")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/1590412138-13903-1-git-send-email-yangtiezhu@loongson.cnSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/phy/rockchip/phy-rockchip-inno-dsidphy.c

@@ -607,8 +607,8 @@ static int inno_dsidphy_probe(struct platform_device *pdev)
 	platform_set_drvdata(pdev, inno);
 
 	inno->phy_base = devm_platform_ioremap_resource(pdev, 0);
-	if (!inno->phy_base)
-		return -ENOMEM;
+	if (IS_ERR(inno->phy_base))
+		return PTR_ERR(inno->phy_base);
 
 	inno->ref_clk = devm_clk_get(dev, "ref");
 	if (IS_ERR(inno->ref_clk)) {