erlang: Fix several compilation warnings

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@990999 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/erl/src/thrift_binary_protocol.erl b/lib/erl/src/thrift_binary_protocol.erl
index 9216e47..800fd8e 100644
--- a/lib/erl/src/thrift_binary_protocol.erl
+++ b/lib/erl/src/thrift_binary_protocol.erl
@@ -187,7 +187,7 @@
             %% there's a version number but it's unexpected
             {This1, {error, {bad_binary_protocol_version, Sz}}};
 
-        {ok, Sz} when This1#binary_protocol.strict_read =:= true ->
+        {ok, _Sz} when This1#binary_protocol.strict_read =:= true ->
             %% strict_read is true and there's no version header; that's an error
             {This1, {error, no_binary_protocol_version}};