Don't bother initializing the junk buffer, we really don't care.
The array was also unnecessary and ugly.

Also, avoid returning the byte count we read/wrote since it
unnecessarily exposes internal details of the implementation to
the callers.

git-svn-id: https://svn.musicpd.org/mpd/trunk@7219 09075e82-0dd4-0310-85a5-a0d7c8717e4f