[PATCH] epic100: fix counting of work_done in epic_poll

work_done is overwritten each time through the rx_action loop in
epic_poll.  This screws-up the NAPI accounting if the loop is executed
more than once.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>