[PATCH] forcedeth: fix multi irq issues

With Manfred Spraul <manfred@colorfullife.com> and
     Andrew Morton <akpm@osdl.org>

Bring back this recently-reverted patch, only fixed.

Original changelog:

    From: Ayaz Abdulla <aabdulla@nvidia.com>

    This patch fixes the issues with multiple irqs.

    I am resending based on feedback. I decoupled the dma mask for
    consistent memory and fixed leak with multiple irq in error path.

    Thanks to Manfred for catching the spin lock problem.

Fix it:

    From: Manfred Spraul <manfred@colorfullife.com>

    Fix bug introduced by ebf34c9, covered in
    http://bugzilla.kernel.org/show_bug.cgi?id=6568.

    Remove second instance of the request_irq() calls: they were moved
    from nv_open into nv_request_irq.

    Thanks to Alistair Strachan <alistair@devzero.co.uk> for reporting and
    persisting.

Signed-off-by: Ayaz Abdulla <aabdulla@nvidia.com>
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>