nft: Fix for broken recover_rule_compat()

nft: Fix for broken recover_rule_compat()

When IPv4 rule generator was changed to emit payload instead of
meta expressions for l4proto matches, the code reinserting
NFTNL_RULE_COMPAT_* attributes into rules being reused for counter
zeroing was broken by accident.

Make rule compat recovery aware of the alternative match, basically
reinstating the effect of commit 7a373f6683afb ("nft: Fix -Z for rules
with NFTA_RULE_COMPAT") but add a test case this time to make sure
things stay intact.

Fixes: 69278f9602b43 ("nft: use payload matching for layer 4 protocol")
Signed-off-by: Phil Sutter <phil@nwl.cc>