[llvm] [MIRPrinter] Don't print space when there is no successor (PR #80143)

[Jay Foad via llvm-commits]

jayfoad wrote:

> > > This also prints two line breaks, and I think we can delete one.
> > 
> > But you haven't done that in this patch, right?
> 
> This breaks many test cases. If appropriate, I'll create another PR.

I find it a little confusing to even mention it in the commit message, if the commit does not change it.

https://github.com/llvm/llvm-project/pull/80143