regmap: maple: Switch to use kmemdup_array()

Let the kememdup_array() take care about multiplication and possible
overflows.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240606164717.3031107-5-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: andy-shev

drivers/base/regmap/regcache-maple.c

@@ -132,9 +132,9 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 			lower_index = mas.index;
 			lower_last = min -1;
 
-			lower = kmemdup(entry, ((min - mas.index) *
-						sizeof(unsigned long)),
-					map->alloc_flags);
+			lower = kmemdup_array(entry,
+					      min - mas.index, sizeof(*lower),
+					      map->alloc_flags);
 			if (!lower) {
 				ret = -ENOMEM;
 				goto out_unlocked;
@@ -145,10 +145,9 @@ static int regcache_maple_drop(struct regmap *map, unsigned int min,
 			upper_index = max + 1;
 			upper_last = mas.last;
 
-			upper = kmemdup(&entry[max - mas.index + 1],
-					((mas.last - max) *
-					 sizeof(unsigned long)),
-					map->alloc_flags);
+			upper = kmemdup_array(&entry[max - mas.index + 1],
+					      mas.last - max, sizeof(*upper),
+					      map->alloc_flags);
 			if (!upper) {
 				ret = -ENOMEM;
 				goto out_unlocked;