Return a std::unique_ptr when creating a new MemoryBuffer.

llvm-svn: 216583
diff --git a/llvm/unittests/Support/YAMLParserTest.cpp b/llvm/unittests/Support/YAMLParserTest.cpp
index 6374638..823a0d6 100644
--- a/llvm/unittests/Support/YAMLParserTest.cpp
+++ b/llvm/unittests/Support/YAMLParserTest.cpp
@@ -210,8 +210,8 @@
 
   // When we construct a YAML stream over a named buffer,
   // we get its ID as filename in diagnostics.
-  std::unique_ptr<MemoryBuffer> Buffer(
-      MemoryBuffer::getMemBuffer("[]", "buffername.yaml"));
+  std::unique_ptr<MemoryBuffer> Buffer =
+      MemoryBuffer::getMemBuffer("[]", "buffername.yaml");
   yaml::Stream Stream(Buffer->getMemBufferRef(), SM);
   Stream.printError(Stream.begin()->getRoot(), "Hello, World!");
   EXPECT_EQ("buffername.yaml", GeneratedDiag.getFilename());