Fix "too many arguments" messages not to index off the end of argv[].

This affects initdb, clusterdb, reindexdb, and vacuumdb in master
and 9.2; in earlier branches, only initdb is affected.

src/bin/initdb/initdb.c

@@ -3012,7 +3012,7 @@ main(int argc, char *argv[])
 	if (optind < argc)
 	{
 		fprintf(stderr, _("%s: too many command-line arguments (first is \"%s\")\n"),
-				progname, argv[optind + 1]);
+				progname, argv[optind]);
 		fprintf(stderr, _("Try \"%s --help\" for more information.\n"),
 				progname);
 		exit(1);

src/bin/scripts/clusterdb.c

@@ -125,7 +125,7 @@ main(int argc, char *argv[])
 	if (optind < argc)
 	{
 		fprintf(stderr, _("%s: too many command-line arguments (first is \"%s\")\n"),
-				progname, argv[optind + 1]);
+				progname, argv[optind]);
 		fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 		exit(1);
 	}

src/bin/scripts/reindexdb.c

@@ -135,7 +135,7 @@ main(int argc, char *argv[])
 	if (optind < argc)
 	{
 		fprintf(stderr, _("%s: too many command-line arguments (first is \"%s\")\n"),
-				progname, argv[optind + 1]);
+				progname, argv[optind]);
 		fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 		exit(1);
 	}

src/bin/scripts/vacuumdb.c

@@ -149,7 +149,7 @@ main(int argc, char *argv[])
 	if (optind < argc)
 	{
 		fprintf(stderr, _("%s: too many command-line arguments (first is \"%s\")\n"),
-				progname, argv[optind + 1]);
+				progname, argv[optind]);
 		fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
 		exit(1);
 	}