Fixed broken TIFFOpen function in LibTiff interface unit.

Fixed broken TIFFOpen function in LibTiff interface unit.

• Demos/ObjectPascal/LCLImager/mainunit.pas
• Extras/Extensions/LibTiff/ImagingTiffLib.pas
• Extras/Extensions/LibTiff/LibDelphi.pas
• Extras/Extensions/LibTiff/LibTiffDelphi.pas
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