lsof: Fix build
lsof: Fix build

- Running `brew install --interactive lsof` revealed that the man page
  name is now capitalized?!
- Should probably push this upstream to Homebrew/homebrew-core, but
  that's _several more merges_ away and this is currently blocking our
  Linux users.

Closes #14663.

Signed-off-by: Issy Long <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@issyl0.co.uk>

Linuxbrew/homebrew-core,rwhogg/homebrew-core,rwhogg/homebrew-core,LinuxbrewTestBot/homebrew-core,LinuxbrewTestBot/homebrew-core,maxim-belkin/homebrew-core,Linuxbrew/homebrew-core,maxim-belkin/homebrew-core