mini2440: start.S set buzzer on

Signed-off-by: Fudong Bai <fudongbai@gmail.com>
mini2440: buzzer off when board early init

Signed-off-by: Fudong Bai <fudongbai@gmail.com>
boot_usb: fix report error when it is pretty normal

usb_bulk_write will return the bytes actuall wrote to the usb device,
but orginal code will return an error when the return value is not zero,
which is not correct.

Signed-off-by: Fudong Bai <fudongbai@gmail.com>