Merge branch 'rj/branch-do-not-exit-with-minus-one-status'

"git branch --edit-description" can exit with status -1 which is
not a good practice; it learned to use 1 as everybody else instead.

* rj/branch-do-not-exit-with-minus-one-status:
  branch: error code with --edit-description

diff --cc builtin/branch.c
Simple merge

diff --cc t/t3200-branch.sh
Simple merge