replay: Improve error messages about configuration conflicts

Improve

   Record/replay feature is not supported for '-rtc base=localtime'
   Record/replay feature is not supported for 'smp'
   Record/replay feature is not supported for '-snapshot'

to

   Record/replay is not supported with -rtc base=localtime
   Record/replay is not supported with multiple CPUs
   Record/replay is not supported with -snapshot

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Pavel Dovgalyuk <Pavel.Dovgalyuk@ispras.ru>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

replay/replay.c

@@ -511,7 +511,7 @@ void replay_add_blocker(const char *feature)
 {
     Error *reason = NULL;
 
-    error_setg(&reason, "Record/replay feature is not supported for '%s'",
+    error_setg(&reason, "Record/replay is not supported with %s",
                feature);
     replay_blockers = g_slist_prepend(replay_blockers, reason);
 }

system/vl.c

@@ -1932,7 +1932,7 @@ static void qemu_apply_machine_options(QDict *qdict)
     }
 
     if (current_machine->smp.cpus > 1) {
-        replay_add_blocker("smp");
+        replay_add_blocker("multiple CPUs");
     }
 }