erlang: Spell behaviour properly

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@990965 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/erl/src/thrift_binary_protocol.erl b/lib/erl/src/thrift_binary_protocol.erl
index ad53384..a681acf 100644
--- a/lib/erl/src/thrift_binary_protocol.erl
+++ b/lib/erl/src/thrift_binary_protocol.erl
@@ -19,7 +19,7 @@
 
 -module(thrift_binary_protocol).
 
--behavior(thrift_protocol).
+-behaviour(thrift_protocol).
 
 -include("thrift_constants.hrl").
 -include("thrift_protocol.hrl").