Merge branch 'cs/don-t-pretend-a-failed-remote-set-head-succeeded'

"git remote set-head" that failed still said something that hints
the operation went through, which was misleading.

* cs/don-t-pretend-a-failed-remote-set-head-succeeded:
  remote: don't show success message when set-head fails

diff --cc builtin/remote.c
Simple merge