the issue is reported at #1759.

bps does not need any C++ library functions in bcc.
It only needs libbpf. So link it with bpf-static instead
of bcc-static. This avoids pulling in any C++ module/symbolization/usdt
functions and llvm libraries.

On my local box, the binary size is reduced from ~60MB to 44KB.
Signed-off-by: Yonghong Song <yhs@fb.com>