net/bnxt: fix Rx buffer posting

net/bnxt: fix Rx buffer posting

Remove early buffer posting logic from burst receive loop to address
several issues:
   - Posting receive descriptors without first posting completion
     entries risks overflowing the completion queue.
   - Posting receive descriptors without updating rx_raw_prod
     creates the possibility that the receive descriptor doorbell
     can be written twice with the same value.
   - Having this logic in the inner descriptor processing loop
     can impact performance.

Fixes: 637e34befd9c ("net/bnxt: optimize Rx processing")
Fixes: 04067844a3e9 ("net/bnxt: reduce CQ queue size without aggregation ring")
Cc: stable@dpdk.org
Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>