adding logs to a daemon store can fail before the entire request has
been read, leaving non-command data in socket buffers. if the daemon
does not terminate immediately after the failure it will try to read
the remaining data as commands, which is very likely to not work and
cause unbounded memory allocation instead. this doesn't give clients
an attack vector they did not have before though, they could've just
as well sent malformed commands without a bad preceding AddBuildLog.
Change-Id: I86c22890eace19164d932cbd342ac9f52cee6531