Don't ignore return value of qemuProcessKill

When calling qemuProcessKill from the virDomainDestroy impl
in QEMU, do not ignore the return value. This ensures that
if QEMU fails to respond to SIGKILL, the caller will know
about the failure.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
(cherry picked from commit f1b4021b)

src/qemu/qemu_driver.c

@@ -1955,7 +1955,11 @@ qemuDomainDestroyFlags(virDomainPtr dom,
             goto cleanup;
         }
     } else {
-        ignore_value(qemuProcessKill(driver, vm, VIR_QEMU_PROCESS_KILL_FORCE));
+        if (qemuProcessKill(driver, vm, VIR_QEMU_PROCESS_KILL_FORCE) < 0) {
+            virReportError(VIR_ERR_OPERATION_FAILED, "%s",
+                           _("failed to kill qemu process with SIGTERM"));
+            goto cleanup;
+        }
     }
 
     /* We need to prevent monitor EOF callback from doing our work (and sending