Remove deadlock in ot_terminate()

The method acquires a lock on the static mutex `the_Mutex`.

It then calls itself recursively by re-throwing the exception and hangs because
it has already acquired the lock.

This freezes the process on my Linux system, but it should freeze on other
systems as well.

Unclear purpose, removed.

The mutex used in the signal handler code has the same issue.

src/core/OTLog.cpp

@@ -294,7 +294,7 @@ int OTLogStream::overflow(int c)
     return 0;
 }
 
-//  OTLog Init, must run this befor useing any OTLog function.
+//  OTLog Init, must run this before using any OTLog function.
 
 // static
 bool OTLog::Init(const OTString& strThreadContext, const int32_t& nLogLevel)
@@ -945,10 +945,6 @@ static const bool SET_TERMINATE = std::set_terminate(ot_terminate);
 //
 void ot_terminate()
 {
-    static std::mutex the_Mutex;
-
-    std::lock_guard<std::mutex> lock(the_Mutex);
-
     try {
         // try once to re-throw currently active exception
         static bool tried_throw = false;