[gnome-sudoku] Fix use of ngettext

[Michael Catanzaro <mcatanzaro src gnome org>]

commit efdd4467c0abf26f0c8439d680944179fd3987c2
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Sat Sep 6 14:35:14 2014 -0500

    Fix use of ngettext
    
    At this rate, we may never get this string to work!
    
    https://bugzilla.gnome.org/show_bug.cgi?id=731139

 src/gnome-sudoku.vala |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/gnome-sudoku.vala b/src/gnome-sudoku.vala
index 5afcd16..1516133 100644
--- a/src/gnome-sudoku.vala
+++ b/src/gnome-sudoku.vala
@@ -246,9 +246,10 @@ public class Sudoku : Gtk.Application
             saver.add_game_to_finished (game, true);
 
             /* Text in dialog that displays when the game is over. */
+            var minutes = int.max (1, (int) game.get_total_time_played () / 60);
             var time_str = ngettext ("Well done, you completed the puzzle in %d minute",
                                      "Well done, you completed the puzzle in %d minutes",
-                                     int.max (1, (int) game.get_total_time_played () / 60));
+                                     minutes).printf (minutes);
             var dialog = new MessageDialog (window, DialogFlags.DESTROY_WITH_PARENT, MessageType.INFO, 
ButtonsType.NONE, time_str);
 
             dialog.add_button (_("Same difficulty again"), 0);