Merge branch 'rj/complete-worktree-paths-fix'

The logic to complete the command line arguments to "git worktree"
subcommand (in contrib/) has been updated to correctly honor things
like "git -C dir" etc.

* rj/complete-worktree-paths-fix:
  completion: fix __git_complete_worktree_paths

diff --cc contrib/completion/git-completion.bash
Simple merge

diff --cc t/t9902-completion.sh
Simple merge