clk: zynqmp: Fix memory allocation in zynqmp_clk_setup

Fix memory allocation and use struct_size() in kzalloc(). This also
fixes the allocation size to be correct, and smaller, because before we
were allocating a bunch of sizeof(struct clk_hw_onecell_data) structures
for each struct clk_hw we needed.

Fixes: 3fde0e1 ("drivers: clk: Add ZynqMP clock driver")
Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
[sboyd@kernel.org: Expand commit text]
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/zynqmp/clkc.c

@@ -669,8 +669,8 @@ static int zynqmp_clk_setup(struct device_node *np)
 	if (ret)
 		return ret;
 
-	zynqmp_data = kzalloc(sizeof(*zynqmp_data) + sizeof(*zynqmp_data) *
-						clock_max_idx, GFP_KERNEL);
+	zynqmp_data = kzalloc(struct_size(zynqmp_data, hws, clock_max_idx),
+			      GFP_KERNEL);
 	if (!zynqmp_data)
 		return -ENOMEM;