pull: do not abuse 'break' inside a shell 'case'

It is not C. The code would break under mksh when 'pull.ff' is set:

  $ git pull
  /usr/lib/git-core/git-pull[67]: break: can't break
  Already up-to-date.

Signed-off-by: Jacek Konieczny <jajcus@jajcus.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Merge branch 'jc/rev-parse-argh-dashed-multi-words' into maint

* jc/rev-parse-argh-dashed-multi-words:
  update-index: fix segfault with missing --cacheinfo argument
Sync with maint

* maint:
  pull: do not abuse 'break' inside a shell 'case'