this patch fix the following error :
  CC      drivers/usb/gadget/epautoconf.o
drivers/usb/gadget/epautoconf.c:33: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'unsigned'
drivers/usb/gadget/epautoconf.c: In function 'ep_matches':
drivers/usb/gadget/epautoconf.c:168: error: 'epnum' undeclared (first use in this function)
drivers/usb/gadget/epautoconf.c:168: error: (Each undeclared identifier is reported only once
drivers/usb/gadget/epautoconf.c:168: error: for each function it appears in.)
drivers/usb/gadget/epautoconf.c: In function 'usb_ep_autoconfig_reset':
drivers/usb/gadget/epautoconf.c:304: error: 'epnum' undeclared (first use in this function)

Signed-off-by: Eric Bénard <eric@eukrea.com>