sysutils/nut: Remove unnecessary validation for bus_num

The libusb_get_bus_number() function serves as a simple accessor for
the bus number of the opaque device struct. Unlike
libusb_get_port_number(), it does not have the ability to convey
errors back to the caller, and a bus number of 0 is a valid value.
Therefore, any validation around bus_num is redundant.

This commit removes the unnecessary validation code related to bus_num.

Signed-off-by: Xin LI <delphij@FreeBSD.org>

PR:			275293
Upstream commit:	4aeb199eb
Upstream Pull Request:	networkupstools/nut#2198

sysutils/nut/Makefile

@@ -1,6 +1,6 @@
 PORTNAME=	nut
 PORTVERSION=	2.8.1
-PORTREVISION=	1
+PORTREVISION=	2
 CATEGORIES=	sysutils
 MASTER_SITES=	http://www.networkupstools.org/source/${PORTVERSION:R}/
 

sysutils/nut/files/patch-drivers_libusb1.c

@@ -0,0 +1,18 @@
+--- drivers/libusb1.c.orig	2023-11-24 07:19:04.377537000 -0800
++++ drivers/libusb1.c	2023-11-24 07:20:06.065188000 -0800
+@@ -263,14 +263,7 @@
+ 			libusb_free_device_list(devlist, 1);
+ 			fatal_with_errno(EXIT_FAILURE, "Out of memory");
+ 		}
+-		if (bus_num > 0) {
+-			sprintf(curDevice->Bus, "%03d", bus_num);
+-		} else {
+-			upsdebugx(1, "%s: invalid libusb bus number %i",
+-				__func__, bus_num);
+-			free(curDevice->Bus);
+-			curDevice->Bus = NULL;
+-		}
++		sprintf(curDevice->Bus, "%03d", bus_num);
+
+ 		device_addr = libusb_get_device_address(device);
+ 		curDevice->Device = (char *)malloc(4);