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/memory_buffer.c b/lib/rb/ext/memory_buffer.c
index a607ae2..00545cc 100644
--- a/lib/rb/ext/memory_buffer.c
+++ b/lib/rb/ext/memory_buffer.c
@@ -49,4 +49,4 @@
   slice_method_id = rb_intern("slice");
   
   GARBAGE_BUFFER_SIZE = FIX2INT(rb_const_get(thrift_memory_buffer_class, rb_intern("GARBAGE_BUFFER_SIZE")));
-}
\ No newline at end of file
+}