Fix fdo#70807: Page Style method isInUse() broken

We need to check m_FirstMaster and m_FirstLeft too to verify is a style is used

Thanks a lot mst__ for pointing how to fix this!

Change-Id: Ic9c37c552893c17fba4aabcc0fd4beb7fe2550e8
Reviewed-on: https://gerrit.libreoffice.org/7295Reviewed-by: Michael Stahl <mstahl@redhat.com>
Tested-by: Olivier Hallot <olivier.hallot@edx.srv.br>

sw/source/core/layout/pagedesc.cxx

@@ -157,13 +157,16 @@ void SwPageDesc::ResetAllAttr( sal_Bool bLeft )
 |*
 *************************************************************************/
 
-
-    // gets information from Modify
+// gets information from Modify
 bool SwPageDesc::GetInfo( SfxPoolItem & rInfo ) const
 {
     if( !aMaster.GetInfo( rInfo ) )
-            return false;       // found
-    return aLeft.GetInfo( rInfo );
+        return false;       // found
+    if ( !aLeft.GetInfo( rInfo ) )
+        return false ;
+    if ( !m_FirstMaster.GetInfo( rInfo ) )
+        return false;
+    return m_FirstLeft.GetInfo( rInfo );
 }
 
 /*************************************************************************