Please commit this fix to a race in the audio/liba52 port

[Chad J. Milios]

Sorry to be a pest. At the bottom of closed PR:

http://www.freebsd.org/cgi/query-pr.cgi?pr=ports/183791

There is a working fix that hasn't been committed yet. A target needs to be added to audio/liba52/Makefile I recommend changing it a little bit though from the one in the PR, to this:

pre-install:
    ${FIND} ${WRKSRC} -name Makefile | ${XARGS} ${TOUCH}