[PATCH] usbcore: recovery from Set-Configuration failure

This patch (as703) improves the error handling when a Set-Configuration
request fails.  The old interfaces are all unregistered before the
request is sent, and if the request fails then we don't know what config
the device is using.  So it makes no sense to leave actconfig pointing
to the old configuration with its invalid interfaces.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>