Fix warnings found with clang-cl.

Earlier this week I was able to get clang-cl on Windows to be
able to self host.  This opened the door to being able to
get a whole new slew of warnings for the Windows build.

This patch fixes all of the warnings, many of which were real
bugs.

llvm-svn: 230522

lldb/source/Plugins/Process/Windows/DebuggerThread.cpp

@@ -79,7 +79,6 @@ DebuggerThread::DebuggerThreadRoutine(const ProcessLaunchInfo &launch_info)
     // Grab a shared_ptr reference to this so that we know it won't get deleted until after the
     // thread routine has exited.
     std::shared_ptr<DebuggerThread> this_ref(shared_from_this());
-    Log *log(lldb_private::GetLogIfAllCategoriesSet(LIBLLDB_LOG_PROCESS));
 
     Error error;
     ProcessLauncherWindows launcher;