bpf: tools: Sync uapi bpf.h for the name changes in bpf_func_info

This patch sync the name changes in bpf_func_info to
the tools/.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>