Handle initializing of struct typed output variable correctly.

BUG=angleproject:1441
TEST=webgl2 conformance

Change-Id: Idb27036347e1e814ba4603969cc2065e425ac4aa
Reviewed-on: https://chromium-review.googlesource.com/362641
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Kenneth Russell <kbr@chromium.org>
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
diff --git a/src/compiler/translator/Compiler.cpp b/src/compiler/translator/Compiler.cpp
index 88e8888..8a46b91 100644
--- a/src/compiler/translator/Compiler.cpp
+++ b/src/compiler/translator/Compiler.cpp
@@ -825,7 +825,7 @@
     {
         for (auto var : varyings)
         {
-            sh::ExpandVariable(var, var.name, var.mappedName, false, &list);
+            list.push_back(var);
         }
     }
     else