use long instead of int for strtol, and don't allow queue size to be 0...

ggated/ggated.c

@@ -95,7 +95,7 @@ struct ggd_export {
 	SLIST_ENTRY(ggd_export) e_next;
 };
 
-static int niothreads = 20;
+static long niothreads = 20;
 static const char *exports_file = GGATED_EXPORT_FILE;
 static int got_sighup = 0;
 
@@ -1050,7 +1050,7 @@ main(int argc, char *argv[])
 			break;
 		case 'q':
 			niothreads = strtol(optarg, NULL, 10);
-			if (niothreads < 0)
+			if (niothreads <= 0)
 				errx(EXIT_FAILURE, "Invalid queue size.");
 			break;
 		case 'R':