Set security label on FD for virDomainOpenGraphics

The virDomainOpenGraphics method accepts a UNIX socket FD from
the client app. It must set the label on this FD otherwise QEMU
will be prevented from receiving it with recvmsg.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>

src/qemu/qemu_driver.c

@@ -14777,6 +14777,10 @@ qemuDomainOpenGraphics(virDomainPtr dom,
         goto cleanup;
     }
 
+    if (virSecurityManagerSetImageFDLabel(driver->securityManager, vm->def,
+                                          fd) < 0)
+        goto cleanup;
+
     if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0)
         goto cleanup;
     qemuDomainObjEnterMonitor(driver, vm);