sfc: Map MCDI error MC_CMD_ERR_ENOTSUP to Linux EOPNOTSUPP

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
diff --git a/drivers/net/ethernet/sfc/mcdi.c b/drivers/net/ethernet/sfc/mcdi.c
index aee67be..d317dfd 100644
--- a/drivers/net/ethernet/sfc/mcdi.c
+++ b/drivers/net/ethernet/sfc/mcdi.c
@@ -192,6 +192,8 @@
 	TRANSLATE_ERROR(EALREADY);
 	TRANSLATE_ERROR(ENOSPC);
 #undef TRANSLATE_ERROR
+	case MC_CMD_ERR_ENOTSUP:
+		return -EOPNOTSUPP;
 	case MC_CMD_ERR_ALLOC_FAIL:
 		return -ENOBUFS;
 	case MC_CMD_ERR_MAC_EXIST: