return SvMemoryStream by std::unique_ptr

Change-Id: I60a41111e76d72a7384cbb15f2d2a73c95af8c2d
Reviewed-on: https://gerrit.libreoffice.org/57280
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

include/sot/storage.hxx

@@ -85,7 +85,7 @@ public:
                         SotStorage( bool bUCBStorage, SvStream & rStm );
                         SotStorage( SvStream * pStm, bool bDelete );
 
-    SvMemoryStream *    CreateMemoryStream();
+    std::unique_ptr<SvMemoryStream> CreateMemoryStream();
 
     static bool         IsStorageFile( const OUString & rFileName );
     static bool         IsStorageFile( SvStream* pStream );

sd/source/filter/eppt/eppt.cxx

@@ -1261,7 +1261,7 @@ void PPTWriter::ImplWriteOLE( )
     for ( auto it = maExOleObj.begin(); it != maExOleObj.end(); ++it )
     {
         PPTExOleObjEntry* pPtr = it->get();
-        SvMemoryStream* pStrm = nullptr;
+        std::unique_ptr<SvMemoryStream> pStrm;
         pPtr->nOfsB = mpStrm->Tell();
         switch ( pPtr->eType )
         {
@@ -1324,7 +1324,7 @@ void PPTWriter::ImplWriteOLE( )
             aZCodec.BeginCompression();
             aZCodec.Compress( *pStrm, *mpStrm );
             aZCodec.EndCompression();
-            delete pStrm;
+            pStrm.reset();
             mpPptEscherEx->EndAtom( EPP_ExOleObjStg, 0, 1 );
         }
     }

sot/source/sdstor/storage.cxx

@@ -456,10 +456,9 @@ SotStorage::~SotStorage()
         delete m_pStorStm;
 }
 
-SvMemoryStream * SotStorage::CreateMemoryStream()
+std::unique_ptr<SvMemoryStream> SotStorage::CreateMemoryStream()
 {
-    SvMemoryStream * pStm = nullptr;
-    pStm = new SvMemoryStream( 0x8000, 0x8000 );
+    std::unique_ptr<SvMemoryStream> pStm(new SvMemoryStream( 0x8000, 0x8000 ));
     tools::SvRef<SotStorage> aStg = new SotStorage( *pStm );
     if( CopyTo( aStg.get() ) )
     {
@@ -468,8 +467,7 @@ SvMemoryStream * SotStorage::CreateMemoryStream()
     else
     {
         aStg.clear(); // release storage beforehand
-        delete pStm;
-        pStm = nullptr;
+        pStm.reset();
     }
     return pStm;
 }