extcon: arizona: Use devm_kcalloc() in arizona_extcon_get_micd_configs()

* A multiplication for the size determination of a memory allocation
  indicated that an array data structure should be processed.
  Thus use the corresponding function "devm_kcalloc".

* Replace the specification of a data structure by a pointer dereference
  to make the corresponding size determination a bit safer according to
  the Linux coding style convention.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Reviewed-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>

drivers/extcon/extcon-arizona.c

@@ -1271,9 +1271,7 @@ static int arizona_extcon_get_micd_configs(struct device *dev,
 		goto out;
 
 	nconfs /= entries_per_config;
-
-	micd_configs = devm_kzalloc(dev,
-				    nconfs * sizeof(struct arizona_micd_range),
+	micd_configs = devm_kcalloc(dev, nconfs, sizeof(*micd_configs),
 				    GFP_KERNEL);
 	if (!micd_configs) {
 		ret = -ENOMEM;