net: stmmac: Correct the error message about invalid speed

The message about invalid speed does not state 1000 as a valid speed.
It is much simpler to said that the speed is invalid.
Signed-off-by: NCorentin Labbe <clabbe.montjoie@gmail.com>
Acked-by: NGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

@@ -738,8 +738,7 @@ static void stmmac_adjust_link(struct net_device *dev)
 				break;
 			default:
 				netif_warn(priv, link, priv->dev,
-					   "Speed (%d) not 10/100\n",
-					   phydev->speed);
+					   "broken speed: %d\n", phydev->speed);
 				break;
 			}