usb: gadget: fix up some comments about CONFIG_USB_DEBUG

These two gadget drivers said that their #endif was for
CONFIG_USB_DEBUG, but they really were not, so fix them up to be
correct.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>