THRIFT-2543 Generated enum type in haskell should be qualified

Client: Haskell
Patch: Zejun Wu
diff --git a/compiler/cpp/src/generate/t_hs_generator.cc b/compiler/cpp/src/generate/t_hs_generator.cc
index d52088b..7a1b505 100644
--- a/compiler/cpp/src/generate/t_hs_generator.cc
+++ b/compiler/cpp/src/generate/t_hs_generator.cc
@@ -1482,7 +1482,7 @@
     }
 
   } else if (type->is_enum()) {
-    return capitalize(((t_enum*)type)->get_name());
+    return type_name((t_enum*)type);
 
   } else if (type->is_struct() || type->is_xception()) {
     return type_name((t_struct*)type);