Cleanups in libjingle to make it compile with chromium_code=1

Fixed all warnings that show up when compiling libjingle
in chromium with compiling with chromium_code=1.
chromium_code=1 enables various warnings that are off by
default. Most changes are for unused variables and consts.

R=pthatcher@google.com, wu@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9699004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5769 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/talk/xmpp/xmppengineimpl.cc b/talk/xmpp/xmppengineimpl.cc
index d4c9c7d..cf07ab7 100644
--- a/talk/xmpp/xmppengineimpl.cc
+++ b/talk/xmpp/xmppengineimpl.cc
@@ -418,8 +418,7 @@
 
 XmppEngineImpl::EnterExit::EnterExit(XmppEngineImpl* engine)
     : engine_(engine),
-  state_(engine->state_),
-  error_(engine->error_code_) {
+      state_(engine->state_) {
   engine->engine_entered_ += 1;
 }