sw mailmerge: Use SfxBaseModel directly, avoid UNO querying

Use the more concrete SfxBaseModel directly that is returned
from SfxObjectShell::GetBaseModel since previous commit

    Change-Id: I05ad3a4bccfb080ccbee3af956451def3bcc94fc
    Author: Michael Weghorn <m.weghorn@posteo.de>
    Date:   Wed Sep 16 17:10:09 2026 +0200

        sfx2: Return concrete type in SfxObjectShell::GetBaseModel

This removes the need to query for the XStorable interface,
as the method can be called directly via the SfxBaseModel
now.

Change-Id: I4328413c819e728214c3d0d218e6713c2cc1c5ce
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/211054
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

sw/source/ui/dbui/mmresultdialogs.cxx

@@ -717,8 +717,8 @@ IMPL_LINK_NOARG(SwMMResultSaveDialog, SaveOutputHdl_Impl, weld::Button&, void)
                 try
                 {
                     pValues[0].Value <<= sFilter;
-                    uno::Reference< frame::XStorable > xTempStore( xTempDocShell->GetModel(), uno::UNO_QUERY);
-                    xTempStore->storeToURL( sOutPath, aValues   );
+                    rtl::Reference<SfxBaseModel> pTempModel = xTempDocShell->GetBaseModel();
+                    pTempModel->storeToURL(sOutPath, aValues);
                 }
                 catch (const uno::Exception&)
                 {