Change OwningPtr::take() to OwningPtr::release().

This is a precursor to moving to std::unique_ptr.

llvm-svn: 203275
diff --git a/clang/lib/Basic/VirtualFileSystem.cpp b/clang/lib/Basic/VirtualFileSystem.cpp
index 28bb598..3775fda 100644
--- a/clang/lib/Basic/VirtualFileSystem.cpp
+++ b/clang/lib/Basic/VirtualFileSystem.cpp
@@ -731,7 +731,7 @@
   if (!P.parse(Root, FS.get()))
     return NULL;
 
-  return FS.take();
+  return FS.release();
 }
 
 ErrorOr<Entry *> VFSFromYAML::lookupPath(const Twine &Path_) {