clk: renesas: mstp: Combine group-private and clock array allocation

Make mstp_clock_group.clks[] a flexible array member, and use the new
struct_size() helper, to combine the allocation of the group-private
structure and array of module clocks.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>

drivers/clk/renesas/clk-mstp.c

@@ -30,11 +30,12 @@
 /**
  * struct mstp_clock_group - MSTP gating clocks group
  *
- * @data: clocks in this group
+ * @data: clock specifier translation for clocks in this group
  * @smstpcr: module stop control register
  * @mstpsr: module stop status register (optional)
  * @lock: protects writes to SMSTPCR
  * @width_8bit: registers are 8-bit, not 32-bit
+ * @clks: clocks in this group
  */
 struct mstp_clock_group {
 	struct clk_onecell_data data;
@@ -42,6 +43,7 @@ struct mstp_clock_group {
 	void __iomem *mstpsr;
 	spinlock_t lock;
 	bool width_8bit;
+	struct clk *clks[];
 };
 
 /**
@@ -186,14 +188,13 @@ static void __init cpg_mstp_clocks_init(struct device_node *np)
 	struct clk **clks;
 	unsigned int i;
 
-	group = kzalloc(sizeof(*group), GFP_KERNEL);
-	clks = kmalloc_array(MSTP_MAX_CLOCKS, sizeof(*clks), GFP_KERNEL);
-	if (group == NULL || clks == NULL) {
+	group = kzalloc(struct_size(group, clks, MSTP_MAX_CLOCKS), GFP_KERNEL);
+	if (group == NULL) {
 		kfree(group);
-		kfree(clks);
 		return;
 	}
 
+	clks = group->clks;
 	spin_lock_init(&group->lock);
 	group->data.clks = clks;
 
@@ -203,7 +204,6 @@ static void __init cpg_mstp_clocks_init(struct device_node *np)
 	if (group->smstpcr == NULL) {
 		pr_err("%s: failed to remap SMSTPCR\n", __func__);
 		kfree(group);
-		kfree(clks);
 		return;
 	}