thermal: rockchip: fix an error code

There is a copy and paste bug, "->clk" vs "->pclk", so we return the
wrong error code here.

Fixes: cbac8f63 ('thermal: rockchip: add driver for thermal')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Caesar Wang <wxt@rock-chips.com>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Tested-by: Caesar Wang <wxt@rock-chips.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/rockchip_thermal.c

@@ -529,7 +529,7 @@ static int rockchip_thermal_probe(struct platform_device *pdev)
 
 	thermal->pclk = devm_clk_get(&pdev->dev, "apb_pclk");
 	if (IS_ERR(thermal->pclk)) {
-		error = PTR_ERR(thermal->clk);
+		error = PTR_ERR(thermal->pclk);
 		dev_err(&pdev->dev, "failed to get apb_pclk clock: %d\n",
 			error);
 		return error;