[PATCH] drivers/base/bus.c: fix iteration in driver_detach()

With 2.6.11 and 2.6.12-rc2 (and perhaps a few versions before) usb
drivers for multi-interface devices, which do
usb_driver_release_interface() in their disconnect(), make rmmod hang.

It turns out to be due to a bug in drivers/base/bus.c:driver_detach(),
that iterates over the list of attached devices with
list_for_each_safe() under an assumption that device_release_driver()
only releases the current device, while it may also call
device_release_driver() for other devices on the same list.

The following patch fixes it.  Please consider applying.

Signed-off-by: Roman Kagan <rkagan@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>