mbuf: mark offload flag as deprecated

mbuf: mark offload flag as deprecated

PKT_RX_EIP_CKSUM_BAD has been declared deprecated but there was no
warning to applications still using it.
Fix this by marking as deprecated with the newly introduced
RTE_DEPRECATED.

Fixes: e8a419d6de4b ("mbuf: rename outer IP checksum macro")

Signed-off-by: David Marchand <david.marchand@redhat.com>
Reviewed-by: Flavio Leitner <fbl@sysclose.org>
Acked-by: Olivier Matz <olivier.matz@6wind.com>
Acked-by: Lance Richardson <lance.richardson@broadcom.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>