net/bnxt: fix fallback mbuf allocation logic

net/bnxt: fix fallback mbuf allocation logic

Fixes for fallback mbuf allocation logic.
   - Preserve raw (unmasked) producer index.
   - Iterate over all processed descriptors (representor and
     non-representor) when checking allocation status.
   - Invoke fallback allocation logic when an allocation
     failure has occurred for any received packet, not
     just the last.

Fixes: 6dc83230b43b ("net/bnxt: support port representor data path")
Fixes: d9dd0b29ed31 ("net/bnxt: fix Rx handling and buffer allocation logic")
Fixes: c7de4195cc4c ("net/bnxt: modify ring index logic")
Cc: stable@dpdk.org
Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>