usb: usb_set_configuration() obeys authorization

Will refuse to configure a non-authorized device.

Update: simplified if statement--thanks to Ragner Magalhaes for the
heads up.

Signed-off-by: Inaky Perez-Gonzalez <inaky@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>