This fixes these gcc warnings (not enabled in default build):

hw/acpi/aml-build.c:83:5: warning:
 function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]
hw/acpi/aml-build.c:88:5: warning:
 function might be possible candidate for ‘gnu_printf’ format attribute [-Wsuggest-attribute=format]

Cc: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: NStefan Weil <sw@weilnetz.de>
Reviewed-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NMichael S. Tsirkin <mst@redhat.com>