clk: sunxi: Use PTR_ERR_OR_ZERO()

Fix ptr_ret.cocci warnings:
drivers/clk/sunxi/clk-sun8i-apb0.c:101:1-3: WARNING: PTR_ERR_OR_ZERO can be used

Use PTR_ERR_OR_ZERO rather than if(IS_ERR(...)) + PTR_ERR

Generated by: scripts/coccinelle/api/ptr_ret.cocci
Signed-off-by: NVasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>

drivers/clk/sunxi/clk-sun8i-apb0.c

@@ -98,10 +98,7 @@ static int sun8i_a23_apb0_clk_probe(struct platform_device *pdev)
 		return PTR_ERR(reg);
 
 	clk = sun8i_a23_apb0_register(np, reg);
-	if (IS_ERR(clk))
-		return PTR_ERR(clk);
-
-	return 0;
+	return PTR_ERR_OR_ZERO(clk);
 }
 
 static const struct of_device_id sun8i_a23_apb0_clk_dt_ids[] = {