thunderbolt: Right shifting to zero bug in tbnet_handle_packet()

There is a problem when we do:

	sequence = pkg->hdr.length_sn & TBIP_HDR_SN_MASK;
	sequence >>= TBIP_HDR_SN_SHIFT;

TBIP_HDR_SN_SHIFT is 27, and right shifting a u8 27 bits is always
going to result in zero.  The fix is to declare these variables as u32.

Fixes: e69b6c02 ("net: Add support for networking over Thunderbolt cable")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>