PM / devfreq: rockchip-dfi: Fix an error message

There is a typo in the message. The clock name should be 'pclk_ddr_mon'.
Fix it.

While at it, switch to dev_err_probe() which is less verbose, filters
-EPROBE_DEFER, and log the error code in a human readable way.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/devfreq/event/rockchip-dfi.c

@@ -189,10 +189,9 @@ static int rockchip_dfi_probe(struct platform_device *pdev)
 		return PTR_ERR(data->regs);
 
 	data->clk = devm_clk_get(dev, "pclk_ddr_mon");
-	if (IS_ERR(data->clk)) {
-		dev_err(dev, "Cannot get the clk dmc_clk\n");
-		return PTR_ERR(data->clk);
-	}
+	if (IS_ERR(data->clk))
+		return dev_err_probe(dev, PTR_ERR(data->clk),
+				     "Cannot get the clk pclk_ddr_mon\n");
 
 	/* try to find the optional reference to the pmu syscon */
 	node = of_parse_phandle(np, "rockchip,pmu", 0);