BUG: warning at kernel/lockdep.c:1816/trace_hardirqs_on() (Not tainted)

Call Trace:
 show_trace
 dump_stack
 trace_hardirqs_on
 :forcedeth:nv_nic_irq_other
 handle_IRQ_event
 __do_IRQ
 do_IRQ
 ret_from_intr
DWARF2 barf
 default_idle
 cpu_idle
 rest_init
 start_kernel
 _sinittext

These 3 functions nv_nic_irq_tx(), nv_nic_irq_rx() and nv_nic_irq_other()
are reachable from IRQ context and process context. Make use of the
irq-save/restore spinlock variant.

(Compile tested only, since I do not have the hardware)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jeff Garzik <jeff@garzik.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>