Apply "exactly fill up the buffer" fix from toybox's bunzip.c.
Apply "exactly fill up the buffer" fix from toybox's bunzip.c.

Quoting the original commit message:

> It's not a problem to exactly fill up the buffer with a run if the
>  next symbol is the terminating symbol. Fixes
> https://jira.cyanogenmod.org/browse/CYAN-1896

See: http://landley.net/hg/toybox/rev/7b6fbc0475d8

cscott/seek-bzip