lxc: Fix lxcDomainDestroyFlags endjob processing

Commit id '15ccb0db' added job functions for the lxc driver; however,
for shutdown and nonpersistent path, the vm was removed from the domain
object list and the vm pointer cleared before the endjob.

Adjust the code to perform the endjob first and then perform the
ObjListRemove as long as the vm wasn't NULL. This follows more closely
models from qemu and libxl

Found by Coverity (FORWARD_NULL)

src/lxc/lxc_driver.c

@@ -1541,13 +1541,11 @@ lxcDomainDestroyFlags(virDomainPtr dom,
                                      VIR_DOMAIN_EVENT_STOPPED_DESTROYED);
     priv->doneStopEvent = true;
     virDomainAuditStop(vm, "destroyed");
-    if (!vm->persistent) {
-        virDomainObjListRemove(driver->domains, vm);
-        vm = NULL;
-    }
 
  endjob:
     virLXCDomainObjEndJob(driver, vm);
+    if (!vm->persistent)
+        virDomainObjListRemove(driver->domains, vm);
 
  cleanup:
     virDomainObjEndAPI(&vm);