Issue #20736: testSendmsgDontWait in test_socket no longer skipped on Linux.

Patch by David Watson.

Lib/test/test_socket.py

@@ -2221,7 +2221,7 @@ class SendmsgStreamTests(SendmsgTests):
     # Linux supports MSG_DONTWAIT when sending, but in general, it
     # only works when receiving.  Could add other platforms if they
     # support it too.
-    @skipWithClientIf(sys.platform not in {"linux2"},
+    @skipWithClientIf(sys.platform not in {"linux"},
                       "MSG_DONTWAIT not known to work on this platform when "
                       "sending")
     def testSendmsgDontWait(self):