libsysutils: Fix a file descriptor leak.

The recent refactoring of the select() loop in SocketListener
missed a close() of the file descriptor when the onDataAvailable()
callback returns false.

Change-Id: I767caefab4b98ab350f2db2497ee2bd630f20850

libsysutils/src/SocketListener.cpp

@@ -225,6 +225,7 @@ void SocketListener::runListener() {
                 }
                 pthread_mutex_unlock(&mClientsLock);
                 /* Destroy the client */
+                close(c->getSocket());
                 delete c;
             }
         }