Fix a regression that severely impacted compression levels.
Regression was introducted in commit 8bbbf564 (Feb 1 19:58:09 2012) when fixing compiler warnings. In src/libFLAC/lpc.c the line: ref[i] = (r/=err); was erroniously removed because the left hand side, ref[i] was never used. Obviously, the correct thing to do was to replace that line with: r /= err; This code has not been officially released. The only people who would have been affected are people who compiled FLAC from git between February and now. The only adverse affect of this error was that compression ratio would have been severely compromised. No audio is lost, and if anyone has a file that compressed with a bad version of FLAC can decompress it to WAV and then re-compress with a fixed version.