Make connection states a proper type.

Change-Id: I809f9b327c832b88dd63151bf7dcb012d88e81c4
diff --git a/adb/transport_local.cpp b/adb/transport_local.cpp
index 5f7449d..d3c4c30 100644
--- a/adb/transport_local.cpp
+++ b/adb/transport_local.cpp
@@ -387,7 +387,7 @@
     t->write_to_remote = remote_write;
     t->sfd = s;
     t->sync_token = 1;
-    t->connection_state = CS_OFFLINE;
+    t->connection_state = kCsOffline;
     t->type = kTransportLocal;
     t->adb_port = 0;