ObserverPathnameExtension: only puts first 100 operations
ObserverPathnameExtension: only puts first 100 operations

Fixes https://github.com/Homebrew/homebrew/issues/44320#issuecomment-143951973

Closes #44440.

Signed-off-by: Xu Cheng <9a05244150b861e40c78843b801eed71bca54eac@me.com>

kwilczynski/homebrew,kwilczynski/homebrew,kwilczynski/homebrew,kwilczynski/homebrew