hmp: Simplify qom-set

Simplify qom_set by making it use qmp_qom_set and the JSON parser.

(qemu) qom-get /machine smm
"auto"
(qemu) qom-set /machine smm "auto"

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200520151108.160598-3-dgilbert@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  With 's'->'S' type change suggested by Paolo and Markus

hmp-commands.hx

@@ -1806,7 +1806,7 @@ ERST
 
     {
         .name       = "qom-set",
-        .args_type  = "path:s,property:s,value:s",
+        .args_type  = "path:s,property:s,value:S",
         .params     = "path property value",
         .help       = "set QOM property",
         .cmd        = hmp_qom_set,

qom/qom-hmp-cmds.c

@@ -48,19 +48,13 @@ void hmp_qom_set(Monitor *mon, const QDict *qdict)
     const char *property = qdict_get_str(qdict, "property");
     const char *value = qdict_get_str(qdict, "value");
     Error *err = NULL;
-    bool ambiguous = false;
-    Object *obj;
+    QObject *obj;
 
-    obj = object_resolve_path(path, &ambiguous);
-    if (obj == NULL) {
-        error_set(&err, ERROR_CLASS_DEVICE_NOT_FOUND,
-                  "Device '%s' not found", path);
-    } else {
-        if (ambiguous) {
-            monitor_printf(mon, "Warning: Path '%s' is ambiguous\n", path);
-        }
-        object_property_parse(obj, value, property, &err);
+    obj = qobject_from_json(value, &err);
+    if (err == NULL) {
+        qmp_qom_set(path, property, obj, &err);
     }
+
     hmp_handle_error(mon, err);
 }