nfp: xsk: avoid newline at the end of message in NL_SET_ERR_MSG_MOD

Fix the following coccicheck warning:
drivers/net/ethernet/netronome/nfp/nfp_net_common.c:3434:8-48: WARNING
avoid newline at end of message in NL_SET_ERR_MSG_MOD
Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -3431,7 +3431,7 @@ nfp_net_check_config(struct nfp_net *nn, struct nfp_net_dp *dp,
 
 		if (xsk_pool_get_rx_frame_size(dp->xsk_pools[r]) < xsk_min_fl_bufsz) {
 			NL_SET_ERR_MSG_MOD(extack,
-					   "XSK buffer pool chunk size too small\n");
+					   "XSK buffer pool chunk size too small");
 			return -EINVAL;
 		}
 	}