bug: git format prints no final newline

This command omits the final newline:

git log --format=format:"%H"

check with: `| tail | cat -A`

This command doesn't, but there is an extra newline between each line of course:

git log --format=format:"%H%n"

This seems to be intentional in the code, a newline is printed before each line except the first:

https://github.com/git/git/blob/master/log-tree.c#L664

It seems more correct to print a newline after every line, but the code is very hairy so I am keen to get any feedback before attempting that.

Thanks