Merge branch 'bpf-bpftool-mount-tracefs'

Quentin Monnet says:

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This series focus on mounting (or not mounting) tracefs with bpftool.

First patch makes bpftool attempt to mount tracefs if tracefs is not
found when running "bpftool prog tracelog".

Second patch adds an option to bpftool to prevent it from attempting
to mount any file system (tracefs or bpffs), in case this behaviour
is undesirable for some users.
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Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>