Free the network IRQ when closing down the network devices at shutdown.
Delete the device from the opened devices list on close.

These prevent an -EBADF when later disabling SIGIO on all extant descriptors
and a complaint from free_irq about freeing the IRQ twice.
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>