manibuilder/anita: Use QEMU's -drive option over -hdb

Current QEMU wants us to specify the `raw` format explicitly and
limits write access otherwise. So use the more elaborate `-drive`
syntax.

Change-Id: If5f74592736ec4e0ef971a9a55bbdeb534358dd4
Signed-off-by: Nico Huber <nico.h@gmx.de>
2 files changed