iio: Use kmalloc_array() in iio_scan_mask_set()

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

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Signed-off-by: NJonathan Cameron <jic23@kernel.org>

drivers/iio/industrialio-buffer.c

@@ -307,10 +307,9 @@ static int iio_scan_mask_set(struct iio_dev *indio_dev,
 	const unsigned long *mask;
 	unsigned long *trialmask;
 
-	trialmask = kmalloc(sizeof(*trialmask)*
-			    BITS_TO_LONGS(indio_dev->masklength),
-			    GFP_KERNEL);
-
+	trialmask = kmalloc_array(BITS_TO_LONGS(indio_dev->masklength),
+				  sizeof(*trialmask),
+				  GFP_KERNEL);
 	if (trialmask == NULL)
 		return -ENOMEM;
 	if (!indio_dev->masklength) {