[PATCH] staging: greybus: power_supply: Use struct_size() helper

["Gustavo A. R. Silva" <gustavo@embeddedor.com>]

Make use of the struct_size() helper instead of an open-coded version
in order to avoid any potential type mistakes, in particular in the
context in which this code is being used.

So, replace code of the following form:

sizeof(*resp) + props_count * sizeof(struct gb_power_supply_props_desc)

with:

struct_size(resp, props, props_count)

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/staging/greybus/power_supply.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/staging/greybus/power_supply.c b/drivers/staging/greybus/power_supply.c
index 0529e5628c24..40cc2d462ba0 100644
--- a/drivers/staging/greybus/power_supply.c
+++ b/drivers/staging/greybus/power_supply.c
@@ -520,8 +520,8 @@ static int gb_power_supply_prop_descriptors_get(struct gb_power_supply *gbpsy)
 
 	op = gb_operation_create(connection,
 				 GB_POWER_SUPPLY_TYPE_GET_PROP_DESCRIPTORS,
-				 sizeof(req), sizeof(*resp) + props_count *
-				 sizeof(struct gb_power_supply_props_desc),
+				 sizeof(req),
+				 struct_size(resp, props, props_count),
 				 GFP_KERNEL);
 	if (!op)
 		return -ENOMEM;
-- 
2.21.0