qemu: reset VM id after external devices stop

pid filenames (from swtpm and other helpers from this series) are
based on VM shortname, which is derived from VM id. If the id is reset
to early, the state filenames will not be found.
Signed-off-by: NMarc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: NMichal Privoznik <mprivozn@redhat.com>

src/qemu/qemu_process.c

@@ -7418,8 +7418,6 @@ void qemuProcessStop(virQEMUDriverPtr driver,
 
     qemuProcessBuildDestroyMemoryPaths(driver, vm, NULL, false);
 
-    vm->def->id = -1;
-
     if (virAtomicIntDecAndTest(&driver->nactive) && driver->inhibitCallback)
         driver->inhibitCallback(false, driver->inhibitOpaque);
 
@@ -7495,6 +7493,8 @@ void qemuProcessStop(virQEMUDriverPtr driver,
 
     qemuExtDevicesStop(driver, vm);
 
+    vm->def->id = -1;
+
     /* Stop autodestroy in case guest is restarted */
     qemuProcessAutoDestroyRemove(driver, vm);