net/fsl: Add format length modifier to avoid negative values

Signed-off-by: NShruti Kanetkar <Shruti@Freescale.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/xgmac_mdio.c

@@ -163,7 +163,7 @@ static int xgmac_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 	/* Return all Fs if nothing was there */
 	if (in_be32(&regs->mdio_stat) & MDIO_STAT_RD_ER) {
 		dev_err(&bus->dev,
-			"Error while reading PHY%d reg at %d.%d\n",
+			"Error while reading PHY%d reg at %d.%hhu\n",
 			phy_id, dev_addr, regnum);
 		return 0xffff;
 	}