Get rid of the mdelay call in rhine_disable_linkmon.  The function
is called from the via-rhine versions of mdio_read and mdio_write.
Those functions are indirectly called from rhine_check_media and
rhine_tx_timeout, both of which can be called in interrupt context.

So, create tx_timeout_task and check_media_task as instances of struct
work_struct inside of rhine_private.  Then, change rhine_tx_timeout to
invoke schedule_work for tx_timeout_task (i.e. rhine_tx_timeout_task),
moving the work to process context.  Also, change rhine_error (invoked
from rhine_interrupt) to invoke schedule_work for check_media_task
(i.e. rhine_check_media_task), which simply calls rhine_check media
in process context.  Finally, add a call to flush_scheduled_work in
rhine_close to avoid any resource conflicts with pending work items.

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