[clang-tidy] modernize-pass-by-value bugfix. Reverting lit-style test

Adding to revision 270565. The lit-style test was wrong. This is being fixed by this commit.

This is the bug on bugzilla: https://llvm.org/bugs/show_bug.cgi?id=27731

This is the code review on phabricator: http://reviews.llvm.org/D20365

llvm-svn: 270567