Fix error with SmallString implicit conversion.

llvm-svn: 341597
diff --git a/llvm/lib/Testing/Support/SupportHelpers.cpp b/llvm/lib/Testing/Support/SupportHelpers.cpp
index 2b26e9e..5f53b23 100644
--- a/llvm/lib/Testing/Support/SupportHelpers.cpp
+++ b/llvm/lib/Testing/Support/SupportHelpers.cpp
@@ -30,11 +30,9 @@
   if (llvm::sys::fs::is_regular_file(PathInParentDir))
     return std::make_pair(true, std::move(PathInParentDir));
 
-  return std::pair<bool, SmallString<128>>(false, "");
+  return std::pair<bool, SmallString<128>>(false, {});
 }
 
-static bool isInParentDir(StringRef Argv0) {}
-
 SmallString<128> llvm::unittest::getInputFileDirectory(const char *Argv0) {
   bool Found = false;
   SmallString<128> InputFilePath;