clk: rockchip: Fix error pointer check after rockchip_clk_register_gate_link()

Replace NULL check with IS_ERR_OR_NULL() check after calling
rockchip_clk_register_gate_link() since this function
returns error pointers (ERR_PTR).

Fixes: c62fa61 ("clk: rockchip: implement linked gate clock support")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://patch.msgid.link/20250805030358.3665878-1-linmq006@gmail.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: Yuuoniy

drivers/clk/rockchip/clk.c

@@ -693,7 +693,7 @@ void rockchip_clk_register_late_branches(struct device *dev,
 			break;
 		}
 
-		if (!pdev)
+		if (IS_ERR_OR_NULL(pdev))
 			dev_err(dev, "failed to register device for clock %s\n", list->name);
 	}
 }