host: return 0 network stats if invalid input

src/host.c

@@ -818,7 +818,7 @@ static unsigned long long get_netdev_stats(char *device, char *stat)
 	unsigned long long val = 0;
 
 	if (!device || !stat)
-		return 1;
+		return 0;
 
 	snprintf(sysnet, 128, "/sys/class/net/%s/statistics/%s", device, stat);