Revert "NefDecoder::decodeRawInternal(): don't stack-allocate NikonDecompressor."
Revert "NefDecoder::decodeRawInternal(): don't stack-allocate NikonDecompressor."

This reverts commit b19d8ac56ea4e2ad4006a32bd9d1abc68f7ab5c9.

Stack size of NikonDecompressor has been reduced otherwise.

darktable-org/rawspeed,anarsoul/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,LebedevRI/rawspeed,anarsoul/rawspeed,darktable-org/rawspeed,darktable-org/rawspeed,LebedevRI/rawspeed,anarsoul/rawspeed,darktable-org/rawspeed