This command can be used to print the version of the tool, which is in
fact the version from Linux taken from usr/include/linux/version.h.

Example usage:

    $ bpftool version
    bpftool v4.14.0
Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: NDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>