net: make sure net_rx_action() calls skb_defer_free_flush()

I missed a stray return; in net_rx_action(), which very well
is taken whenever trigger_rx_softirq() has been called on
a cpu that is no longer receiving network packets,
or receiving too few of them.

Fixes: 68822bdf ("net: generalize skb freeing deferral to per-cpu lists")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://lore.kernel.org/r/20220427204147.1310161-1-eric.dumazet@gmail.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>