netxen: remove timespec usage

netxen_collect_minidump() evidently just wants to get a monotonic
timestamp. Using jiffies_to_timespec(jiffies, &ts) is not
appropriate here, since it will overflow after 2^32 jiffies,
which may be as short as 49 days of uptime.

ktime_get_seconds() is the correct interface here.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>