nfp: fix flower offload metadata flag usage

[ Upstream commit 6c3ab204f4ca00374a374bc0fc9a275b64d1bcbb ]

Hardware has no notion of new or last mask id, instead it makes use of the
message type (i.e. add flow or del flow) in combination with a single bit
in metadata flags to determine when to add or delete a mask id. Previously
we made use of the new or last flags to indicate that a new mask should be
allocated or deallocated, respectively. This incorrect behaviour is fixed
by making use single bit in metadata flags to indicate mask allocation or
deallocation.

Fixes: 43f84b72 ("nfp: add metadata to each flow offload")
Signed-off-by: Pieter Jansen van Vuuren <pieter.jansenvanvuuren@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>