[obj2yaml] Fix ASAN bot failure

I was leaking out of a unique_ptr, should have just kept it in the unique_ptr.

http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux-fast/builds/12738/steps/check-llvm%20asan/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269336 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed