Fix lower bits of blue being the wrong color in interpolated pixels.
Fix lower bits of blue being the wrong color in interpolated pixels.

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