adb: fix a fake data race on transport:kick reported by tsan.

It is reported by tsan as a double checked locking. But I think
it is not a real data race. Because I think the old code is able
to make sure t->kick() is only called once, and the caller of
kick_transport is not relying on the side-effect of calling
t->kick().
But as it is not perf critical, I don't mind breaking the double
checked locking pattern.

Bug: 23385662
Change-Id: Ie3597dd56bb514117c3865d2afcfd7c115731a78

adb/transport.cpp

@@ -43,7 +43,7 @@ ADB_MUTEX_DEFINE( transport_lock );
 
 void kick_transport(atransport* t)
 {
-    if (t && !t->kicked)
+    if (t != nullptr)
     {
         int  kicked;