Fix 'extra tokens at end of #endif directive' warning

Change-Id: I464ede415e64cf7db845bb441754120974bcf855
diff --git a/adb/transport_local.c b/adb/transport_local.c
index d985ee3..105c502 100644
--- a/adb/transport_local.c
+++ b/adb/transport_local.c
@@ -318,7 +318,7 @@
             /* Running inside the device: use TCP socket as the transport. */
             func = server_socket_thread;
         }
-#endif !ADB_HOST
+#endif // !ADB_HOST
     }
 
     D("transport: local %s init\n", HOST ? "client" : "server");