Issue #16714: use 'raise' exceptions, don't 'throw'.

Patch by Serhiy Storchaka.
diff --git a/Lib/tempfile.py b/Lib/tempfile.py
index 34dff30..b8fc18c 100644
--- a/Lib/tempfile.py
+++ b/Lib/tempfile.py
@@ -625,7 +625,7 @@
 
     def __init__(self, suffix="", prefix=template, dir=None):
         self._closed = False
-        self.name = None # Handle mkdtemp throwing an exception
+        self.name = None # Handle mkdtemp raising an exception
         self.name = mkdtemp(suffix, prefix, dir)
 
     def __repr__(self):