windowscodecs: DibDecoder_CreateInstance() is unused so remove it.

[Matteo Bruni]

2015-01-05 20:10 GMT+01:00 Vincent Povirk <madewokherd at gmail.com>:
> The original intent was that this could be used by d3dx9 to implement
> reading of the DIB format, but I didn't have the knowledge of d3dx9 to
> test that this really does what is needed.

I'm not really familiar with that part of d3dx9 but I see a
convert_dib_to_bmp function in surface.c which suggests that a WIC DIB
decoder is probably unnecessary for d3dx9.