headsup: llvm now uses official bpf e_machine value

just pushed Richard's patch
https://github.com/llvm-mirror/llvm/commit/36b9c09330bfb5e771914cfe307588f30d5510d2

tested with bcc and different bpf loaders.
Thankfully none of them rely on old and arguably
buggy em_none value, so no breakage expected.
if you're using special bpf elf loader, please test.

Thanks