RDMA/bnxt_re: Fix IB_SEND_IP_CSUM handling in post_send

The bnxt_re SEND path checks wr->send_flags to enable features such as
IP checksum offload. However, send_flags is a bitmask and may contain
multiple flags (e.g. IB_SEND_SIGNALED | IB_SEND_IP_CSUM), while the
existing code uses a switch() statement that only matches when
send_flags is exactly IB_SEND_IP_CSUM.

As a result, checksum offload is not enabled when additional SEND
flags are present.

Replace the switch() with a bitmask test:

    if (wr->send_flags & IB_SEND_IP_CSUM)

This ensures IP checksum offload is enabled correctly when multiple
SEND flags are used.

Fixes: 1ac5a40 ("RDMA/bnxt_re: Add bnxt_re RoCE driver")
Signed-off-by: Alok Tiwari <alok.a.tiwari@oracle.com>
Link: https://patch.msgid.link/20251219093308.2415620-1-alok.a.tiwari@oracle.com
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>

Author: aloktiwa

drivers/infiniband/hw/bnxt_re/ib_verbs.c

@@ -2919,14 +2919,9 @@ int bnxt_re_post_send(struct ib_qp *ib_qp, const struct ib_send_wr *wr,
 				wqe.rawqp1.lflags |=
 					SQ_SEND_RAWETH_QP1_LFLAGS_ROCE_CRC;
 			}
-			switch (wr->send_flags) {
-			case IB_SEND_IP_CSUM:
+			if (wr->send_flags & IB_SEND_IP_CSUM)
 				wqe.rawqp1.lflags |=
 					SQ_SEND_RAWETH_QP1_LFLAGS_IP_CHKSUM;
-				break;
-			default:
-				break;
-			}
 			fallthrough;
 		case IB_WR_SEND_WITH_INV:
 			rc = bnxt_re_build_send_wqe(qp, wr, &wqe);