ebtables: Fix entries count in chain listing

ebtables: Fix entries count in chain listing

The previous fix for reference counts in iptables-nft output wasn't
complete: While iptables lists the number of references for each custom
chain (i.e., the number of jumps to it), ebtables lists number of
entries (i.e., the number of rules contained) for each chain. Both used
the same value for it, although they are different metrics.

Fix this by passing both numbers separately to the 'print_header'
callback so that each tool may print the desired value.

Fixes: a0698de9866d2 ("xtables: Do not count rules as chain references")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>