tests: qemuxml2xml: Simplify adding to the status XML expect string generator

Unindent the static XML block and move around the autoindent calls so
that further additions don't have to add more of them.

Also rename the string holding the static XML section.

tests/qemuxml2xmltest.c

@@ -81,23 +81,23 @@ static const char testStatusXMLPrefixHeader[] =
 "  <taint flag='high-privileges'/>\n"
 "  <monitor path='/var/lib/libvirt/qemu/test.monitor' json='1' type='unix'/>\n";
 
-static const char testStatusXMLPrefixFooter[] =
-"  <qemuCaps>\n"
-"    <flag name='vnet-hdr'/>\n"
-"    <flag name='qxl.vgamem_mb'/>\n"
-"    <flag name='qxl-vga.vgamem_mb'/>\n"
-"    <flag name='pc-dimm'/>\n"
-"  </qemuCaps>\n"
-"  <devices>\n"
-"    <device alias='balloon0'/>\n"
-"    <device alias='video0'/>\n"
-"    <device alias='serial0'/>\n"
-"    <device alias='net0'/>\n"
-"    <device alias='usb'/>\n"
-"  </devices>\n"
-"  <numad nodeset='0-2' cpuset='1,3'/>\n"
-"  <libDir path='/tmp'/>\n"
-"  <channelTargetDir path='/tmp/channel'/>\n";
+static const char testStatusXMLPrefixBodyStatic[] =
+"<qemuCaps>\n"
+"  <flag name='vnet-hdr'/>\n"
+"  <flag name='qxl.vgamem_mb'/>\n"
+"  <flag name='qxl-vga.vgamem_mb'/>\n"
+"  <flag name='pc-dimm'/>\n"
+"</qemuCaps>\n"
+"<devices>\n"
+"  <device alias='balloon0'/>\n"
+"  <device alias='video0'/>\n"
+"  <device alias='serial0'/>\n"
+"  <device alias='net0'/>\n"
+"  <device alias='usb'/>\n"
+"</devices>\n"
+"<numad nodeset='0-2' cpuset='1,3'/>\n"
+"<libDir path='/tmp'/>\n"
+"<channelTargetDir path='/tmp/channel'/>\n";
 
 static const char testStatusXMLSuffix[] =
 "</domstatus>\n";
@@ -134,8 +134,9 @@ testGetStatusXMLPrefix(const struct testInfo *data)
 
     testGetStatuXMLPrefixVcpus(&buf, data);
 
+    virBufferAddStr(&buf, testStatusXMLPrefixBodyStatic);
+
     virBufferAdjustIndent(&buf, -2);
-    virBufferAdd(&buf, testStatusXMLPrefixFooter, -1);
 
     return virBufferContentAndReset(&buf);
 }