thermal/drivers/sprd: Fix return value of sprd_thm_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: 554fdbaf ("thermal: sprd: Add Spreadtrum thermal driver support")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/1590371941-25430-1-git-send-email-yangtiezhu@loongson.cn

drivers/thermal/sprd_thermal.c

@@ -348,8 +348,8 @@ static int sprd_thm_probe(struct platform_device *pdev)
 
 	thm->var_data = pdata;
 	thm->base = devm_platform_ioremap_resource(pdev, 0);
-	if (!thm->base)
-		return -ENOMEM;
+	if (IS_ERR(thm->base))
+		return PTR_ERR(thm->base);
 
 	thm->nr_sensors = of_get_child_count(np);
 	if (thm->nr_sensors == 0 || thm->nr_sensors > SPRD_THM_MAX_SENSOR) {