tests: assume JSON in qemuMonitorTestIO

The QMP monitor only uses a newline to separate lines,
while HMP and the guest agent also use a carriage return.

In preparation to dropping support for testing HMP interaction,
only skip the carriage return if we're dealing with the guest agent,
removing the need to check the 'json' field.

Signed-off-by: Ján Tomko <jtomko@redhat.com>
Reviewed-by: Andrea Bolognani <abologna@redhat.com>

tests/qemumonitortestutils.c

@@ -296,7 +296,7 @@ qemuMonitorTestIO(virNetSocketPtr sock,
          */
         t1 = test->incoming;
         while ((t2 = strstr(t1, "\n")) ||
-                (!test->json && (t2 = strstr(t1, "\r")))) {
+                (test->agent && (t2 = strstr(t1, "\r")))) {
             *t2 = '\0';
 
             if (qemuMonitorTestProcessCommand(test, t1) < 0) {