scripts/qmp: Fix shebang and imports

scripts/qmp: Fix shebang and imports

There's more wrong with these scripts; They are in various stages of
disrepair. That's beyond the scope of this current patchset.

This just mechanically corrects the imports and the shebangs, as part of
ensuring that the python/qemu/lib refactoring didn't break anything
needlessly.

Signed-off-by: John Snow <jsnow@redhat.com>
Message-Id: <20200528222129.23826-2-jsnow@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>