usb: use usb_serial_put in usb_serial_probe errors

The use of kfree(serial) in error cases of usb_serial_probe
was invalid - usb_serial structure allocated in create_serial()
gets reference of usb_device that needs to be put, so we need
to use usb_serial_put() instead of simple kfree().

Signed-off-by: Jan Safrata <jan.nikitenko@gmail.com>
Acked-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/serial/usb-serial.c

@@ -757,7 +757,7 @@ static int usb_serial_probe(struct usb_interface *interface,
 
 		if (retval) {
 			dbg("sub driver rejected device");
-			kfree(serial);
+			usb_serial_put(serial);
 			module_put(type->driver.owner);
 			return retval;
 		}
@@ -829,7 +829,7 @@ static int usb_serial_probe(struct usb_interface *interface,
 		 */
 		if (num_bulk_in == 0 || num_bulk_out == 0) {
 			dev_info(&interface->dev, "PL-2303 hack: descriptors matched but endpoints did not\n");
-			kfree(serial);
+			usb_serial_put(serial);
 			module_put(type->driver.owner);
 			return -ENODEV;
 		}
@@ -843,7 +843,7 @@ static int usb_serial_probe(struct usb_interface *interface,
 		if (num_ports == 0) {
 			dev_err(&interface->dev,
 			    "Generic device with no bulk out, not allowed.\n");
-			kfree(serial);
+			usb_serial_put(serial);
 			module_put(type->driver.owner);
 			return -EIO;
 		}