test: qemu: Fix qemu monitor test utils to allow testing HMP

qemu HMP commands sent by libvirt are terminated just by a '\r'. The
fake monitor used in tests wasn't prepared to handle this and the
communication would hang on an attempt to do a HMP conversation.

Add a special case for handling commands separated by \r in case HMP is
used.

tests/qemumonitortestutils.c

@@ -251,7 +251,8 @@ qemuMonitorTestIO(virNetSocketPtr sock,
          * if so, handle that command
          */
         t1 = test->incoming;
-        while ((t2 = strstr(t1, "\n"))) {
+        while ((t2 = strstr(t1, "\n")) ||
+                (!test->json && (t2 = strstr(t1, "\r")))) {
             *t2 = '\0';
 
             if (qemuMonitorTestProcessCommand(test, t1) < 0) {