bnxt_en: Return relevant error code when offload fails

The driver returns -ENOSPC when tc_can_offload() check fails. Since that
routine checks for flow parameters that are not supported by the driver,
we should return the more appropriate -EOPNOTSUPP.
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt_tc.c

@@ -1290,7 +1290,7 @@ static int bnxt_tc_add_flow(struct bnxt *bp, u16 src_fid,
 		bnxt_tc_set_flow_dir(bp, flow, src_fid);
 
 	if (!bnxt_tc_can_offload(bp, flow)) {
-		rc = -ENOSPC;
+		rc = -EOPNOTSUPP;
 		goto free_node;
 	}