Use proper bool operations

Change-Id: Ie02ec90ec8c95e6552f0c8f7344b3a6dbfca84ea
diff --git a/include/tools/stream.hxx b/include/tools/stream.hxx
index 7551a59..1316bc1 100644
--- a/include/tools/stream.hxx
+++ b/include/tools/stream.hxx
@@ -283,7 +283,7 @@ public:
    /// Enable/disable swapping of endians, may be needed for Unicode import/export
    inline void     SetEndianSwap( bool bVal );
    /// returns status of endian swap flag
    bool            IsEndianSwap() const { return 0 != bSwap; }
    bool            IsEndianSwap() const { return bSwap; }

    void            SetCompressMode( sal_uInt16 nNewMode )
                        { nCompressMode = nNewMode; }