smsc95xx: fix smsc_crc return type

This patch fixes a bug introduced in bbd9f9e which could prevent
some wakeups from working correctly if multiple wol options were
selected.

This helper function calculates a 16-bit crc and shifts it into
either the high or low 16 bits of a u32 so the caller can or it
directly into place.  The function previously had a u16 return
type so would always have returned zero when filter was odd.

Signed-off-by: Steve Glendinning <steve.glendinning@shawell.net>
Reported-by: Bjorn Mork <bjorn@mork.no>
Cc: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/smsc95xx.c

@@ -1074,9 +1074,10 @@ static void smsc95xx_unbind(struct usbnet *dev, struct usb_interface *intf)
 	}
 }
 
-static u16 smsc_crc(const u8 *buffer, size_t len, int filter)
+static u32 smsc_crc(const u8 *buffer, size_t len, int filter)
 {
-	return bitrev16(crc16(0xFFFF, buffer, len)) << ((filter % 2) * 16);
+	u32 crc = bitrev16(crc16(0xFFFF, buffer, len));
+	return crc << ((filter % 2) * 16);
 }
 
 static int smsc95xx_enable_phy_wakeup_interrupts(struct usbnet *dev, u16 mask)