VC5Decompressor::decode(): use std::array<> for subband_{band,wavelet}_index
VC5Decompressor::decode(): use std::array<> for subband_{band,wavelet}_index

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