Fix buildbot capture warning

A bot didn't like my lambda. This ought to fix it.

Example:

http://lab.llvm.org:8011/builders/lld-x86_64-win7/builds/30139/steps/build%20lld/logs/stdio

error C3493: 'AlreadyRemoved' cannot be implicitly captured because no default
capture mode has been specified

llvm-svn: 348421