ring: set_sockopt_tpacket: rename to set_sockopt_tpacket_v2

Rename it to set_sockopt_tpacket_v2 so that we later on can also
add other versions and have it clearly stated which one we use.

Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
netsniff-ng: Add __maybe_unused attribute to timer functions

The two functions timer_elapsed() and timer_next_dump() both take an
argument which they don't use. Annotate them appropriately using the
__maybe_unused attribute.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
ifpps: Allow to select number of top hitter CPUs by command line option

Instead of hard-coding the maximum number of top hitter CPUs, allow the
user to set it manually using a command line option. The default value
(if no command line parameter is specified) remains at 10.

Also update the manpage accordingly.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>