Clamp initial value for Nikon decoder to avoid buffer overflow.
Clamp initial value for Nikon decoder to avoid buffer overflow.

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