Limit the number of recoveries from a NIC hw watchdog reset to 1 by default.
It enables detection of defective NICs immediately since these memory parity
errors are expected to happen very rarely (less than once per century*NIC).

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>