ARM: imx: fix the return value check in imx_clk_busy_divider()

In case of error, the function clk_register() returns ERR_PTR()
no NULL pointer. The NULL test in the return value check should
be replaced with IS_ERR().

dpatch engine is used to auto generated this patch.
(https://github.com/weiyj/dpatch)

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/mach-imx/clk-busy.c

@@ -108,7 +108,7 @@ struct clk *imx_clk_busy_divider(const char *name, const char *parent_name,
 	busy->div.hw.init = &init;
 
 	clk = clk_register(NULL, &busy->div.hw);
-	if (!clk)
+	if (IS_ERR(clk))
 		kfree(busy);
 
 	return clk;