clk: sprd: Check error only for devm_regmap_init_mmio()

The function devm_regmap_init_mmio() wouldn't return NULL pointer for
now, so only need to ensure the return value is not an error code.
Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Reviewed-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/sprd/common.c

@@ -58,7 +58,7 @@ int sprd_clk_regmap_init(struct platform_device *pdev,
 
 		regmap = devm_regmap_init_mmio(&pdev->dev, base,
 					       &sprdclk_regmap_config);
-		if (IS_ERR_OR_NULL(regmap)) {
+		if (IS_ERR(regmap)) {
 			pr_err("failed to init regmap\n");
 			return PTR_ERR(regmap);
 		}