Pass a std::unique_ptr& to the create??? methods is lib/Object.

This makes the buffer ownership on error conditions very natural. The buffer
is only moved out of the argument if an object is constructed that now
owns the buffer.

llvm-svn: 211546
diff --git a/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp b/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
index 29f0c87..0eb6e4f 100644
--- a/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
+++ b/llvm/tools/llvm-dwarfdump/llvm-dwarfdump.cpp
@@ -73,7 +73,7 @@
     return;
   }
 
-  ErrorOr<ObjectFile*> ObjOrErr(ObjectFile::createObjectFile(Buff.release()));
+  ErrorOr<ObjectFile *> ObjOrErr(ObjectFile::createObjectFile(Buff));
   if (std::error_code EC = ObjOrErr.getError()) {
     errs() << Filename << ": " << EC.message() << '\n';
     return;