Fix a leak found by asan.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@221179 91177308-0d34-0410-b5e6-96231b3b80d8
Fix leak found by asan.

git-svn-id: https://llvm.org/svn/llvm-project/lld/trunk@221180 91177308-0d34-0410-b5e6-96231b3b80d8