Use getXWeak in fpicker

Change-Id: Iedeb452d49718b6e73a526da132bc0fc9b165fb7
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/150852
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>

fpicker/source/aqua/SalAquaFolderPicker.mm

@@ -79,7 +79,7 @@ sal_Int16 SAL_CALL SalAquaFolderPicker::execute()
         break;
 
     default:
-        throw uno::RuntimeException("The dialog returned with an unknown result!", static_cast< cppu::OWeakObject * >( this ));
+        throw uno::RuntimeException("The dialog returned with an unknown result!", getXWeak());
         break;
     }
 
@@ -117,7 +117,7 @@ OUString SAL_CALL SalAquaFolderPicker::getDirectory()
     SAL_INFO("fpicker.aqua", "# of items: " << nFiles);
 
     if (nFiles < 1) {
-        throw uno::RuntimeException("no directory selected", static_cast< cppu::OWeakObject * >( this ));
+        throw uno::RuntimeException("no directory selected", getXWeak());
     }
 
     OUString aDirectory;

fpicker/source/office/OfficeFilePicker.cxx

@@ -881,7 +881,7 @@ void SAL_CALL SvtFilePicker::appendFilterGroup( const OUString& sGroupTitle,
     if ( FilterNameExists( aFilters ) )
         throw IllegalArgumentException(
             "filter name exists",
-            static_cast< OWeakObject * >(this), 1);
+            getXWeak(), 1);
 
     // ensure that we have a filter list
     OUString sInitialCurrentFilter;