added explict casts for strdup since many includes don't prototype

it.  gag me.

sudo.c

@@ -400,7 +400,7 @@ static void load_globals(sudo_mode)
     if ((tty = (char *) ttyname(0)) || (tty = (char *) ttyname(1))) {
 	if (strncmp(tty, _PATH_DEV, sizeof(_PATH_DEV) - 1) == 0)
 	    tty += sizeof(_PATH_DEV) - 1;
-	if ((tty = strdup(tty)) == NULL) {
+	if ((tty = (char *) strdup(tty)) == NULL) {
 	    perror("malloc");
 	    (void) fprintf(stderr, "%s: cannot allocate memory!\n", Argv[0]);
 	    exit(1);