media: usb: use kmalloc_array() to replace kmalloc()

Use kmalloc_array() to replace kmalloc() with multiplication.
kmalloc_array() has multiply overflow check, which will be safer.

Signed-off-by: Zhang Heng <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/usb/dvb-usb/cxusb-analog.c

···
 		 * doing a large continuous allocation when (if)
 		 * s-g isochronous USB transfers are supported
 		 */
-		streambuf = kmalloc(npackets * CXUSB_VIDEO_PKT_SIZE,
-				    GFP_KERNEL);
+		streambuf = kmalloc_array(npackets, CXUSB_VIDEO_PKT_SIZE,
+					  GFP_KERNEL);
 		if (!streambuf) {
 			if (i < 2) {
 				ret = -ENOMEM;