usb: gadget: coding style fix

fix the coding style of a few switches on the
gadget framework.

[ balbi@ti.com : add a commit log ]

Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>