[otns] fix simulation to use strong otPlatOtnsStatus definition (#5171)

- fix otPlatOtnsStatus(weak) is not used
- use the current openthread rather than openthread master

examples/platforms/utils/otns_utils.cpp

@@ -0,0 +1,49 @@
+/*
+ *  Copyright (c) 2020, The OpenThread Authors.
+ *  All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without
+ *  modification, are permitted provided that the following conditions are met:
+ *  1. Redistributions of source code must retain the above copyright
+ *     notice, this list of conditions and the following disclaimer.
+ *  2. Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *  3. Neither the name of the copyright holder nor the
+ *     names of its contributors may be used to endorse or promote products
+ *     derived from this software without specific prior written permission.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ *  POSSIBILITY OF SUCH DAMAGE.
+ */
+#include <openthread-core-config.h>
+#include <openthread/config.h>
+
+#include <openthread/platform/otns.h>
+#include <openthread/platform/toolchain.h>
+
+#include "common/logging.hpp"
+
+/*
+ * Implementation note:
+ *   These are all "weak" so that a platform may if it chooses to override the instance.
+ */
+
+#if OPENTHREAD_CONFIG_OTNS_ENABLE
+
+OT_TOOL_WEAK
+void otPlatOtnsStatus(const char *aStatus)
+{
+    otLogOtns("[OTNS] %s", aStatus);
+}
+
+#endif // OPENTHREAD_CONFIG_OTNS_ENABLE