Correctly start a search if Return is pressed after a back search

FindNext was early quitting because the previous search was a back search and thus never got to startSearch, now we call startSearch if m_changed
BUGS: 301248
FIXED-IN: 4.9.0

ui/searchlineedit.cpp

@@ -173,7 +173,10 @@ void SearchLineEdit::slotReturnPressed( const QString &text )
 {
     m_inputDelayTimer->stop();
     prepareLineEditForSearch();
-    findNext();
+    if ( m_changed )
+        startSearch();
+    else
+        findNext();
 }
 
 void SearchLineEdit::startSearch()