virtio_console: Use bool function return values of true/false not 1/0

Use the normal return values for bool functions

Signed-off-by: Joe Perches <[e-mail]>
Reviewed-by: Amit Shah <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/char/virtio_console.c

···
 	 * early_init
 	 */
 	if (!portdev->vdev)
-		return 0;
+		return false;
 	return __virtio_test_bit(portdev->vdev, VIRTIO_CONSOLE_F_MULTIPORT);
 }