cid#1465258 Uninitialized pointer field

Change-Id: Ie2646cecfcbf85cc2b24d06786ed9773fcbb7c56
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/98574
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>

svtools/source/brwbox/ebbcontrols.cxx

@@ -387,6 +387,7 @@ namespace svt
 
     EditControlBase::EditControlBase(BrowserDataWin* pParent)
         : ControlBase(pParent, "svt/ui/thineditcontrol.ui", "EditControl") // *thin*editcontrol has no frame/border
+        , m_pEntry(nullptr) // inheritors are expected to call InitEditControlBase
     {
     }