Turn two ifs into one in the code I commited a few days ago

tests/test_install.py

@@ -20,9 +20,8 @@ from distutils.tests import support
 
 
 def _make_ext_name(modname):
-    if os.name == 'nt':
-        if sys.executable.endswith('_d.exe'):
-            modname += '_d'
+    if os.name == 'nt' and sys.executable.endswith('_d.exe'):
+        modname += '_d'
     return modname + sysconfig.get_config_var('SO')