Fix warning in builds without asserts.

llvm-svn: 188132
diff --git a/clang/lib/Tooling/Tooling.cpp b/clang/lib/Tooling/Tooling.cpp
index c5fec68..6f7e7b6 100644
--- a/clang/lib/Tooling/Tooling.cpp
+++ b/clang/lib/Tooling/Tooling.cpp
@@ -133,6 +133,7 @@
   SmallString<1024> AbsolutePath = RelativePath;
   llvm::error_code EC = llvm::sys::fs::make_absolute(AbsolutePath);
   assert(!EC);
+  (void)EC;
   SmallString<1024> PathStorage;
   llvm::sys::path::native(Twine(AbsolutePath), PathStorage);
   return PathStorage.str();