Merge branch 'bpf-helper-man-install'

Quentin Monnet says:

====================
The three patches in this series are related to the documentation for eBPF
helpers. The first patch brings minor formatting edits to the documentation
in include/uapi/linux/bpf.h, and the second one updates the related header
file under tools/.

The third patch adds a Makefile under tools/bpf for generating the
documentation (man pages) about eBPF helpers. The targets defined in this
file can also be called from the bpftool directory (please refer to
relevant commit logs for details).
====================

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>