staging/sbe-2t3e3: Use netdev_ printks in main.c

fixed below checkpatch warning.
- WARNING: Prefer netdev_err(netdev, ... then dev_err(dev, ... then pr_err(...  to printk(KERN_ERR ...
Signed-off-by: NYAMANE Toshiaki <yamanetoshi@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/sbe-2t3e3/main.c

@@ -135,8 +135,9 @@ void t3e3_read_card_serial_number(struct channel *sc)
 	for (i = 0; i < 3; i++)
 		sc->ether.card_serial_number[i] = t3e3_eeprom_read_word(sc, 10 + i);
 
-	printk(KERN_INFO "SBE wanPMC-2T3E3 serial number: %04X%04X%04X\n",
-	       sc->ether.card_serial_number[0], sc->ether.card_serial_number[1],
+	netdev_info(sc->dev, "SBE wanPMC-2T3E3 serial number: %04X%04X%04X\n",
+		    sc->ether.card_serial_number[0],
+		    sc->ether.card_serial_number[1],
 		    sc->ether.card_serial_number[2]);
 }