platform/x86: i2c-multi-instantiate: Use struct_size() helper

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.

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>

diff --git a/drivers/platform/x86/i2c-multi-instantiate.c b/drivers/platform/x86/i2c-multi-instantiate.c
index 197d8a1..61fe341 100644 (file)
--- a/drivers/platform/x86/i2c-multi-instantiate.c
+++ b/drivers/platform/x86/i2c-multi-instantiate.c
@@ -81,9 +81,7 @@ static int i2c_multi_inst_probe(struct platform_device *pdev)
        if (ret < 0)
                return ret;
 
-       multi = devm_kmalloc(dev,
-                       offsetof(struct i2c_multi_inst_data, clients[ret]),
-                       GFP_KERNEL);
+       multi = devm_kmalloc(dev, struct_size(multi, clients, ret), GFP_KERNEL);
        if (!multi)
                return -ENOMEM;