[PATCH v5 2/5] windowscodecs: In find_decoder(), get rid of nested if by using goto, and use IWICWineDecoder_Initialize() to initialize decoders.

[Esme Povirk (they/them)]

The end of the loop checks the interface pointers and releases them,
but it doesn't set them to NULL. This might cause us to release the
interfaces too many times. I suggest moving the declaration of
wine_decoder, decoderinfo, and unkdecoderinfo inside the loop.