Change the clone guest method

1.Delete parameters "image_snapshot = yes"
2.Add other parameters to clone the guest
Signed-off-by: NLei Yang <leiyang@redhat.com>

qemu/tests/cfg/mq_change_qnum.cfg

@@ -7,8 +7,10 @@
     vectors = 10
     virt_test_type = qemu
     type = mq_change_qnum
-    #In this test need set snapshot for our test will chang guest msi support
-    image_snapshot = yes
+    #In this test need to clone the guest to change guest msi support.
+    clone_master = yes
+    master_images_clone = image1
+    remove_image_image1 =yes
     #set repeat_counts for chang queues number
     repeat_counts = 100
     ext_host_get_cmd = "ip route | awk '/default/ { print $3 }'"
@@ -34,7 +36,6 @@
                 - guest_guest:
                     pktgen_server = vm2
                     vms += " vm2"
-                    image_snapshot = yes
                 - host_guest:
                     #host as server
                     password_pktgen_server = redhat