NFC writerfilter numbering: remove redundant code

Remove duplicated StyleSheetImport section,
and redundant valid pointer check.

Change-Id: I468733fc627fbdbebb2daf7087ce9e65158751df
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/92065
Tested-by: Jenkins
Reviewed-by: Justin Luth <justin_luth@sil.org>

writerfilter/source/dmapper/DomainMapper.cxx

@@ -1329,14 +1329,7 @@ void DomainMapper::sprmWithProps( Sprm& rSprm, const PropertyMapPtr& rContext )
             }
             else
             {
-                if( IsStyleSheetImport() )
-                {
-                    // set the number id for AbstractNum references
-                    StyleSheetPropertyMap* pStyleSheetPropertyMap = dynamic_cast< StyleSheetPropertyMap* >( rContext.get() );
-                    if (pStyleSheetPropertyMap)
-                        pStyleSheetPropertyMap->SetNumId( nIntValue );
-                }
-                else
+                if( !IsStyleSheetImport() )
                 {
                     // eg. disabled numbering using non-existent numId "0"
                     rContext->Insert( PROP_NUMBERING_STYLE_NAME, uno::makeAny( OUString() ) );

writerfilter/source/dmapper/NumberingManager.cxx

@@ -464,7 +464,7 @@ OUString ListDef::GetStyleName(sal_Int32 const nId,
     {
         OUString sStyleName = "WWNum" + OUString::number( nId );
 
-        while (xStyles.is() && xStyles->hasByName(sStyleName)) // unique
+        while (xStyles->hasByName(sStyleName)) // unique
         {
             sStyleName += "a";
         }