Merge branch 'jl/commit-v-strip-marker' into maint

"git commit -v" appends the patch to the log message before
editing, and then removes the patch when the editor returned
control. However, the patch was not stripped correctly when the
first modified path was a submodule.

* jl/commit-v-strip-marker:
  commit -v: strip diffs and submodule shortlogs from the commit message