Missed a test case writing a .ll file.

Suppress count output from 'make test' on errors (used to generate
result code).


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@55107 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/cxx-default-arg.cpp b/test/CodeGen/cxx-default-arg.cpp
index 957b60a..017b17d 100644
--- a/test/CodeGen/cxx-default-arg.cpp
+++ b/test/CodeGen/cxx-default-arg.cpp
@@ -1,4 +1,4 @@
-// RUN: clang -emit-llvm %s
+// RUN: clang -emit-llvm %s -o %t
 
 // Note: define CLANG_GENERATE_KNOWN_GOOD and compile to generate code
 // that makes all of the defaulted arguments explicit. The resulting