bpo-30804: fix macOS build with framework enabled. (#2516)

Lib/site.py

@@ -343,8 +343,8 @@ def getsitepackages(prefixes=None):
         # for framework builds *only* we add the standard Apple locations.
         if sys.platform == "darwin" and sys._framework:
             sitepackages.append(
-                    os.path.join("/Library", framework,
-                        '%d.%d' % sys.version_info[:2], "site-packages"))
+                os.path.join("/Library", sys._framework,
+                             '%d.%d' % sys.version_info[:2], "site-packages"))
     return sitepackages
 
 def addsitepackages(known_paths, prefixes=None):