[clang-tidy] Simplify modernize-use-default

Summary:
clang-tidy now cleans up after replacements, so leave colon and comma
removal to that.

Reviewers: angelgarcia, alexfh, aaron.ballman, djasper, ioeric

Subscribers: djasper, cfe-commits

Differential Revision: https://reviews.llvm.org/D25769

llvm-svn: 284735