ionic: remove debug stats

These debug stats are not really useful, their collection is
likely detrimental to performance, and they suck up a lot
of memory which never gets used if no one ever enables the
priv-flag to print them, so just remove these bits.

Signed-off-by: Shannon Nelson <snelson@pensando.io>
Signed-off-by: David S. Miller <davem@davemloft.net>