Add -Wshadow and deal with the warnings.

kpasswd/kpasswd-generator.c

@@ -185,12 +185,12 @@ usage (int ret)
 int
 main(int argc, char **argv)
 {
-    int optind = 0;
+    int optidx = 0;
     int nreq;
     char *end;
 
     setprogname(argv[0]);
-    if(getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &optind))
+    if(getarg(args, sizeof(args) / sizeof(args[0]), argc, argv, &optidx))
 	usage(1);
     if (help_flag)
 	usage (0);
@@ -198,8 +198,8 @@ main(int argc, char **argv)
 	print_version(NULL);
 	return 0;
     }
-    argc -= optind;
-    argv += optind;
+    argc -= optidx;
+    argv += optidx;
 
     if (argc != 2)
 	usage (1);