ofz#11275 erase via position

rather than searching pointer each time

Change-Id: I0db8990b39cce024fbf0bfc6ebd091a5fa210c02
Reviewed-on: https://gerrit.libreoffice.org/66665
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sw/source/core/doc/docredln.cxx

@@ -623,10 +623,11 @@ void SwRedlineTable::Remove( size_type nP )
 
 void SwRedlineTable::DeleteAndDestroyAll()
 {
-    while (!maVector.empty())
+    auto nCount = maVector.size();
+    while (nCount)
     {
         auto const pRedline = maVector.back();
-        maVector.erase(maVector.back());
+        maVector.erase(--nCount);
         LOKRedlineNotification(RedlineNotification::Remove, pRedline);
         delete pRedline;
     }