const_cast: convert some C-style casts and remove some redundant ones

Change-Id: I207f23b084013f9ce2fcf087a7f335bd8a194f50

sdext/source/pdfimport/xpdfwrapper/pdfioutdev_gpl.cxx

@@ -532,7 +532,7 @@ void PDFOutDev::printPath( GfxPath* pPath ) const
 PDFOutDev::PDFOutDev( PDFDoc* pDoc ) :
     m_pDoc( pDoc ),
     m_aFontMap(),
-    m_pUtf8Map( new UnicodeMap((char*)"UTF-8", gTrue, &mapUTF8) ),
+    m_pUtf8Map( new UnicodeMap("UTF-8", gTrue, &mapUTF8) ),
     m_bSkipImages(false)
 {
 }

sdext/source/pdfimport/xpdfwrapper/pdfioutdev_gpl.hxx

@@ -114,7 +114,7 @@ namespace pdfi
 
         bool operator==(const FontAttributes& rFont) const
         {
-            return const_cast<GooString*>(&familyName)->cmp(
+            return familyName.cmp(
                 const_cast<GooString*>(&rFont.familyName))==0 &&
                 isEmbedded == rFont.isEmbedded &&
                 isBold == rFont.isBold &&

sdext/source/pdfimport/xpdfwrapper/pnghelper.cxx

@@ -84,7 +84,7 @@ sal_uInt32 PngHelper::deflateBuffer( const Output_t* i_pBuf, size_t i_nLen, Outp
     aStream.opaque  = Z_NULL;
     deflateInit( &aStream, Z_BEST_COMPRESSION );
     aStream.avail_in = uInt(i_nLen);
-    aStream.next_in = (Bytef*)i_pBuf;
+    aStream.next_in = const_cast<Bytef*>(i_pBuf);
 
     sal_uInt8 aOutBuf[ 32768 ];
     do