Also fixes a GCC 12.0.1 false-positive:
../hw/arm/allwinner-a10.c: In function ‘aw_a10_realize’:
../hw/arm/allwinner-a10.c:135:35: error: ‘%d’ directive writing between 1 and 11 bytes into a region of size 8 [-Werror=format-overflow=]
  135 |             sprintf(bus, "usb-bus.%d", i);
      |                                   ^~

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220420132624.2439741-15-marcandre.lureau@redhat.com>