rockchip_clk_register_ddrclk should not return NULL when failing to call clk_register, otherwise rockchip_clk_register_branches prints "unknown clock type". The actual case is that it's a known clock type but we fail to register it, which may makes user confuse the reason of failure. And the pr_err here is pointless as rockchip_clk_register_branches will also print the similar message. Signed-off-by: Shawn Lin <shawn.lin@rock-chips.com> Signed-off-by: Heiko Stuebner <heiko@sntech.de>