BaseTools: use threading.current_thread in NmakeSubdirs.py

threading.currentThread is a deprecated alias for
threading.current_thread, and causes a warning to be displayed when it's
called. Update NmakeSubdirs.py to use the latter method instead.

Signed-off-by: Rebecca Cran <rebecca@bsdio.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>

BaseTools/Source/C/Makefiles/NmakeSubdirs.py

@@ -132,7 +132,7 @@ class ThreadControl(object):
                 break
 
         self.runningLock.acquire(True)
-        self.running.remove(threading.currentThread())
+        self.running.remove(threading.current_thread())
         self.runningLock.release()
 
 def Run():