net: fib_rules: do not flow dissect local packets

Rules matching on loopback iif do not need early flow dissection as the
packet originates from the host. Stop counting such rules in
fib_rule_requires_fldissect

Signed-off-by: Petar Penkov <ppenkov@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>