tests: qemuxml2xml: Add synthetic test for <lockstate> in status XML

Add a random lockstate string to the status XML2XML test.
Signed-off-by: NPeter Krempa <pkrempa@redhat.com>

tests/qemustatusxml2xmldata/blockjob-mirror-in.xml

@@ -10,6 +10,7 @@
     <flag name='qxl-vga.vgamem_mb'/>
     <flag name='pc-dimm'/>
   </qemuCaps>
+  <lockstate>testtest</lockstate>
   <devices>
     <device alias='balloon0'/>
     <device alias='video0'/>