qapi: Remove QMP events and commands from user-mode builds

We removed the QMP loop in user-mode builds in commit 1935e0e4
("qapi/meson: Remove QMP from user-mode emulation"), now commands
and events code is unreachable.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20210224171642.3242293-1-philmd@redhat.com>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

qapi/meson.build

@@ -102,11 +102,15 @@ foreach module : qapi_all_modules
     'qapi-types-@0@.h'.format(module),
     'qapi-visit-@0@.c'.format(module),
     'qapi-visit-@0@.h'.format(module),
-    'qapi-events-@0@.c'.format(module),
-    'qapi-events-@0@.h'.format(module),
-    'qapi-commands-@0@.c'.format(module),
-    'qapi-commands-@0@.h'.format(module),
   ]
+  if have_system or have_tools
+    qapi_module_outputs += [
+      'qapi-events-@0@.c'.format(module),
+      'qapi-events-@0@.h'.format(module),
+      'qapi-commands-@0@.c'.format(module),
+      'qapi-commands-@0@.h'.format(module),
+    ]
+  endif
   if module.endswith('-target')
     qapi_specific_outputs += qapi_module_outputs
   else