qemu: Fix memory leak in processGuestPanicEvent

After processing the processEvent->data for a qemuProcessEventHandler
callout, it's expected that the called processEvent->eventType helper
will perform the proper free on the data field. In this case it's
a qemuMonitorEventPanicInfoPtr.

src/qemu/qemu_driver.c

@@ -4309,6 +4309,7 @@ processGuestPanicEvent(virQEMUDriverPtr driver,
         qemuDomainRemoveInactiveJob(driver, vm);
 
  cleanup:
+    qemuMonitorEventPanicInfoFree(info);
     virObjectUnref(cfg);
 }