Specifying the wrong driver could fail an assertion:
$ qemu-system-x86_64 -drive file.driver=qcow2,file=x
qemu-system-x86_64: block.c:721: bdrv_open_common: Assertion `file !=
((void *)0)' failed.
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Filter the name of the QEMU executable so the output can be diffed no
matter what QEMU_PROG is (e.g. qemu-system-x86_64).
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>