gusb_device: Add some helpers for reporting not open functionality
gusb_device: Add some helpers for reporting not open functionality

Add some helpers for reporting not open functionality, to avoid code
duplication.

Signed-off-by: Hans de Goede <9fa1be1a5b5729e4c6b404f34c9ce49ff4882fd8@redhat.com>

hughsie/libgusb,nacho/libgusb,hughsie/libgusb,robert-ancell/libgusb,nacho/libgusb,robert-ancell/libgusb,hughsie/libgusb