tools, sc: fix GCC -Werror=type-limits (comparison is always true)

... on 32 bit platforms.  These asserts appear to be impossible anyway.

Change-Id: I6bd332ca49e9992740315e0f6c58e98ac337817c

sc/source/filter/excel/xistream.cxx

@@ -430,7 +430,6 @@ XclImpStream::XclImpStream( SvStream& rInStrm, const XclImpRoot& rRoot, bool bCo
     mrStrm.Seek( STREAM_SEEK_TO_END );
     mnStreamSize = mrStrm.Tell();
     mrStrm.Seek( STREAM_SEEK_TO_BEGIN );
-    OSL_ENSURE( mnStreamSize < STREAM_SEEK_TO_END, "XclImpStream::XclImpStream - stream error" );
 }
 
 XclImpStream::~XclImpStream()

tools/source/stream/stream.cxx

@@ -1769,7 +1769,6 @@ void* SvMemoryStream::SetBuffer( void* pNewBuf, sal_Size nCount,
 
     ResetError();
 
-    DBG_ASSERT( nEndOfData<STREAM_SEEK_TO_END,"Invalid EOF");
     return pResult;
 }