[clang-format] NFC clang-format the clang-format sources

Summary: In recent patches the clang-format code has become un-formatted, correct this before making additional changes

Reviewers: mitchell-stellar, sylvestre.ledru, Abpostelnicu, Wawha, jbcoe

Reviewed By: sylvestre.ledru, Abpostelnicu, jbcoe

Subscribers: cfe-commits

Tags: #clang, #clang-format

Differential Revision: https://reviews.llvm.org/D78909