clk: imx: imx7ulp: use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
    int stuff;
    void *entry[];
};

instance = kzalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_KERNEL);

This issue was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/imx/clk-imx7ulp.c

@@ -48,8 +48,8 @@ static void __init imx7ulp_clk_scg1_init(struct device_node *np)
 	struct clk_hw **clks;
 	void __iomem *base;
 
-	clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws) *
-			   IMX7ULP_CLK_SCG1_END, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_SCG1_END),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;
 
@@ -136,8 +136,8 @@ static void __init imx7ulp_clk_pcc2_init(struct device_node *np)
 	struct clk_hw **clks;
 	void __iomem *base;
 
-	clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws) *
-			   IMX7ULP_CLK_PCC2_END, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_PCC2_END),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;
 
@@ -183,8 +183,8 @@ static void __init imx7ulp_clk_pcc3_init(struct device_node *np)
 	struct clk_hw **clks;
 	void __iomem *base;
 
-	clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws) *
-			   IMX7ULP_CLK_PCC3_END, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_PCC3_END),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;
 
@@ -228,8 +228,8 @@ static void __init imx7ulp_clk_smc1_init(struct device_node *np)
 	struct clk_hw **clks;
 	void __iomem *base;
 
-	clk_data = kzalloc(sizeof(*clk_data) + sizeof(*clk_data->hws) *
-			   IMX7ULP_CLK_SMC1_END, GFP_KERNEL);
+	clk_data = kzalloc(struct_size(clk_data, hws, IMX7ULP_CLK_SMC1_END),
+			   GFP_KERNEL);
 	if (!clk_data)
 		return;