USB: ldusb: use unsigned size format specifiers

A recent info-leak bug manifested itself along with warning about a
negative buffer overflow:

	ldusb 1-1:0.28: Read buffer overflow, -131383859965943 bytes dropped

when it was really a rather large positive one.

A sanity check that prevents this has now been put in place, but let's
fix up the size format specifiers, which should all be unsigned.
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191022143203.5260-3-johan@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/misc/ldusb.c

@@ -487,7 +487,7 @@ static ssize_t ld_usb_read(struct file *file, char __user *buffer, size_t count,
 	}
 	bytes_to_read = min(count, *actual_buffer);
 	if (bytes_to_read < *actual_buffer)
-		dev_warn(&dev->intf->dev, "Read buffer overflow, %zd bytes dropped\n",
+		dev_warn(&dev->intf->dev, "Read buffer overflow, %zu bytes dropped\n",
 			 *actual_buffer-bytes_to_read);
 
 	/* copy one interrupt_in_buffer from ring_buffer into userspace */
@@ -562,8 +562,9 @@ static ssize_t ld_usb_write(struct file *file, const char __user *buffer,
 	/* write the data into interrupt_out_buffer from userspace */
 	bytes_to_write = min(count, write_buffer_size*dev->interrupt_out_endpoint_size);
 	if (bytes_to_write < count)
-		dev_warn(&dev->intf->dev, "Write buffer overflow, %zd bytes dropped\n", count-bytes_to_write);
-	dev_dbg(&dev->intf->dev, "%s: count = %zd, bytes_to_write = %zd\n",
+		dev_warn(&dev->intf->dev, "Write buffer overflow, %zu bytes dropped\n",
+			count - bytes_to_write);
+	dev_dbg(&dev->intf->dev, "%s: count = %zu, bytes_to_write = %zu\n",
 		__func__, count, bytes_to_write);
 
 	if (copy_from_user(dev->interrupt_out_buffer, buffer, bytes_to_write)) {