Merge branch 'bpf-bpftool-misc-fixes'

Jakub Kicinski says:

====================
This series addresses small issues that snuck through the review
of cgroup code.  "list" and "show" are now made aliases to satisfy
all users.  Small fix to errors printed is needed, errors can't
contain new line characters, otherwise JSON will break.
====================

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