THRIFT-302. ruby: Native extension fails to build

A piece of code needed for compilation on Linux was missing; this patch replaces it. Also, there were some compiler warnings and declarations that were missing that are now fixed.

git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@740366 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/rb/ext/struct.h b/lib/rb/ext/struct.h
index bf2350d..870d24e 100644
--- a/lib/rb/ext/struct.h
+++ b/lib/rb/ext/struct.h
@@ -45,4 +45,4 @@
   
 } native_proto_method_table;
 
-void Init_struct();
\ No newline at end of file
+void Init_struct();