usb: gadget: net2272: use false for 'use_dma'

Fix the following coccicheck warning:

drivers/usb/gadget/udc/net2272.c:57:12-19: WARNING: Assignment of 0/1 to
bool variable

Signed-off-by: Jason Yan <yanaijie@huawei.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>