Fix truncated size calculation.
Fix truncated size calculation.

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