[glom/choices_celllayout] Fix typo

[Murray Cumming <murrayc src gnome org>]

commit 2de29c68b675bbdd25058c7ac0da494ca7c0322d
Author: Murray Cumming <murrayc murrayc com>
Date:   Mon Oct 4 09:02:33 2010 +0200

    Fix typo

 .../datawidget/treemodel_db_withextratext.cc       |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glom/mode_data/datawidget/treemodel_db_withextratext.cc b/glom/mode_data/datawidget/treemodel_db_withextratext.cc
index fbf0609..5cd7c0c 100644
--- a/glom/mode_data/datawidget/treemodel_db_withextratext.cc
+++ b/glom/mode_data/datawidget/treemodel_db_withextratext.cc
@@ -78,7 +78,7 @@ void DbTreeModelWithExtraText::get_value_vfunc(const TreeModel::iterator& iter,
 {
   if(column == get_text_column())
   {
-    if(m_item_key)
+    if(!m_item_key)
     {
       std::cerr << G_STRFUNC << ": m_item_key is null." << std::endl;
       return;