Fix the setting of module_dirlen for a module path of "/".

This fixes a crash in the exclude code when chroot is off.

clientserver.c

@@ -321,13 +321,11 @@ static int rsync_module(int f_in, int f_out, int i)
 	/* TODO: Perhaps take a list of gids, and make them into the
 	 * supplementary groups. */
 
-	if (use_chroot) {
+	if (use_chroot || (module_dirlen = strlen(lp_path(i))) == 1) {
 		module_dirlen = 0;
 		set_filter_dir("/", 1);
-	} else {
-		module_dirlen = strlen(lp_path(i));
+	} else
 		set_filter_dir(lp_path(i), module_dirlen);
-	}
 
 	p = lp_filter(i);
 	parse_rule(&server_filter_list, p, MATCHFLG_WORD_SPLIT,