soc: rockchip: power-domain: don't try to print the clock name in error case

When we never got the the clock-reference, i.e. when IS_ERR(clk) is true,
don't try to print the clock name via %pC as this of course produces a
null-pointer-dereference in __clk_get_name().

Signed-off-by: Heiko Stuebner <[e-mail]>
Reviewed-by: Caesar Wang <[e-mail]>

drivers/soc/rockchip/pm_domains.c

···
 		if (IS_ERR(clk)) {
 			error = PTR_ERR(clk);
 			dev_err(pmu->dev,
-				"%s: failed to get clk %pC (index %d): %d\n",
-				node->name, clk, i, error);
+				"%s: failed to get clk at index %d: %d\n",
+				node->name, i, error);
 			goto err_out;
 		}