clk: use IS_ERR_OR_NULL(hw) instead of !hw || IS_ERR(hw)

This minor refactoring does not change the function behavior.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>

drivers/clk/clk.c

@@ -2482,7 +2482,7 @@ struct clk *__clk_create_clk(struct clk_hw *hw, const char *dev_id,
 	struct clk *clk;
 
 	/* This is to allow this function to be chained to others */
-	if (!hw || IS_ERR(hw))
+	if (IS_ERR_OR_NULL(hw))
 		return (struct clk *) hw;
 
 	clk = kzalloc(sizeof(*clk), GFP_KERNEL);