[PATCH] sky2: transmit logic fixes

Some transmit side small fixes:
 * When computing number of list elements per transmit, do full
   comparision to check for checksuming.
 * Get rid of racy check for tx_complete
 * Change stop test to match wake condition.

Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>