NO_DATA is apparently #defined by some header file when building with

NO_DATA is apparently #defined by some header file when building with
MSVC++ on Windows - stick TAP_RTP_ in front of all the error enum
values, to avoid name collisions.

Do *NOT* allocate a zero-length array as an automatic variable,
especially if you're going to assign to the first element of that
array....

git-svn-id: http://anonsvn.wireshark.org/wireshark/trunk@7304 f5534014-38df-0310-8fa8-9805f1628bb7