usb: dwc2: gadget: fix below build warning

linux-2.6/drivers/usb/dwc2/gadget.c: In function 's3c_hsotg_irq_enumdone':
linux-2.6/drivers/usb/dwc2/gadget.c:1904: warning: 'ep_mps' may be used uninitialized in this function

Acked-by: Paul Zimmerman <Paul.Zimmerman@synopsys.com>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>