wsd: simplify shutting down in checkRemoval

It's cleaner to only signal for async-shutdown,
followed by forced shutting down, when the
socket isn't already closed.

Also, repetition is unnecessary.

Change-Id: Ifdc15723bcedccdd432f1bdec9cc335a183e6239
Signed-off-by: Ashod Nakashian <ashod.nakashian@collabora.co.uk>

net/Socket.cpp

@@ -1490,12 +1490,11 @@ bool StreamSocket::checkRemoval(std::chrono::steady_clock::time_point now)
             if (!isClosed())
             {
                 // Note: Ensure proper semantics of onDisconnect()
-                LOG_WRN("Socket still open post onDisconnect(), forced shutdown.");
-                shutdown(); // signal
-                closeConnection(); // real -> setClosed()
+                LOG_WRN("Socket still open post onDisconnect(), forcing shutdown");
             }
         }
-        else
+
+        if (!isClosed())
         {
             shutdown(); // signal
             closeConnection(); // real -> setClosed()