RDMA/bnxt_re: Fix return value of bnxt_re_process_raw_qp_pkt_rx

bnxt_re_process_raw_qp_pkt_rx() always return 0 and ignores the return
value of bnxt_re_post_send_shadow_qp().

Fixes: 1ac5a404

 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Link: https://lore.kernel.org/r/1684397461-23082-3-git-send-email-selvin.xavier@broadcom.com
Reviewed-by: Hongguang Gao <hongguang.gao@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>