monitor: fix client_migrate_info error handling

Report QERR_MISSING_PARAMETER when port is missing. Otherwise
QERR_UNDEFINED_ERROR will occur.

rhbz #795652

Signed-off-by: Yonit Halperin <yhalperi@redhat.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
diff --git a/monitor.c b/monitor.c
index d57e7bf..8f46031 100644
--- a/monitor.c
+++ b/monitor.c
@@ -880,6 +880,11 @@
             return -1;
         }
 
+        if (port == -1 && tls_port == -1) {
+            qerror_report(QERR_MISSING_PARAMETER, "port/tls-port");
+            return -1;
+        }
+
         ret = qemu_spice_migrate_info(hostname, port, tls_port, subject,
                                       cb, opaque);
         if (ret != 0) {