[glom] Another slight code simplification.

[Murray Cumming <murrayc src gnome org>]

commit 5ef420f46a7f1deb2cca92c46e814c82f208007d
Author: Murray Cumming <murrayc murrayc com>
Date:   Thu Sep 10 15:01:06 2015 +0200

    Another slight code simplification.

 glom/mode_design/layout/combobox_relationship.cc |    9 +++++----
 1 files changed, 5 insertions(+), 4 deletions(-)
---
diff --git a/glom/mode_design/layout/combobox_relationship.cc 
b/glom/mode_design/layout/combobox_relationship.cc
index fbda45f..231c4ae 100644
--- a/glom/mode_design/layout/combobox_relationship.cc
+++ b/glom/mode_design/layout/combobox_relationship.cc
@@ -253,6 +253,7 @@ bool ComboBox_Relationship::on_row_separator(const Glib::RefPtr<Gtk::TreeModel>&
 void ComboBox_Relationship::on_cell_data_fromfield(const Gtk::TreeModel::const_iterator& iter)
 {
   Gtk::TreeModel::Row row = *iter;
+  Glib::ustring text;
   std::shared_ptr<Relationship> relationship = row[m_model_columns.m_relationship];
   if(relationship && relationship->get_has_fields())
   {
@@ -261,15 +262,15 @@ void ComboBox_Relationship::on_cell_data_fromfield(const Gtk::TreeModel::const_i
     {
       std::shared_ptr<Relationship> parent_relationship = (*iterParent)[m_model_columns.m_relationship];
       if(parent_relationship)
-        m_renderer_fromfield->property_text() = Glib::ustring::compose(_(" Via: %1::%2"), 
item_get_title(parent_relationship), relationship->get_from_field());
+        text = Glib::ustring::compose(_(" Via: %1::%2"), item_get_title(parent_relationship), 
relationship->get_from_field());
     }
     else
     {
-      m_renderer_fromfield->property_text() = Glib::ustring::compose(_(" Via: %1"), 
relationship->get_to_field());
+      text = Glib::ustring::compose(_(" Via: %1"), relationship->get_to_field());
     }
   }
-  else
-    m_renderer_fromfield->property_text() = Glib::ustring();
+
+  m_renderer_fromfield->property_text() = text;
 }
 
 void ComboBox_Relationship::set_display_parent_table(const Glib::ustring& table_name, const Glib::ustring& 
table_title)