qemu: Fix event generated for qemuDomainRevertToSnapshot (pause->run)

A closer review of the code shows that for the transition from paused to
running which was supposed to emit the VIR_DOMAIN_EVENT_RESUMED - no event
would be generated. Rather the event is generated when going from running
to running.

Following the 'was_running' boolean shows it is set when the domain obj
is active and the domain obj state is VIR_DOMAIN_RUNNING. So rather than
using was_running to generate the RESUMED event, use !was_running

src/qemu/qemu_driver.c

@@ -15549,7 +15549,7 @@ qemuDomainRevertToSnapshot(virDomainSnapshotPtr snapshot,
                 event = virDomainEventLifecycleNewFromObj(vm,
                                                  VIR_DOMAIN_EVENT_STARTED,
                                                  detail);
-            } else if (was_running) {
+            } else if (!was_running) {
                 /* Transition 8 */
                 detail = VIR_DOMAIN_EVENT_RESUMED;
                 event = virDomainEventLifecycleNewFromObj(vm,