net: dsa: felix: print error message in felix_check_xtr_pkt()

Packet extraction failures over register-based MMIO are silent, and
difficult to pinpoint. Add an error message to remedy this.
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/ocelot/felix.c

@@ -1506,8 +1506,12 @@ static bool felix_check_xtr_pkt(struct ocelot *ocelot)
 	}
 
 out:
-	if (err < 0)
+	if (err < 0) {
+		dev_err_ratelimited(ocelot->dev,
+				    "Error during packet extraction: %pe\n",
+				    ERR_PTR(err));
 		ocelot_drain_cpu_queue(ocelot, 0);
+	}
 
 	return true;
 }