[PATCH] remove duplicated resume path code

This gets rid of some inconsistently duplicated logic to resume interfaces.
Similar code was in both finish_port_resume() and in usb_generic_resume().
Now there is just one copy of that code, accessed regardless of whether
CONFIG_USB_SUSPEND is enabled.  Fault handling is also more consistent.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>