Different minor kexec cleanups

[Thomas Renninger]

Hi,

after some holidays and catching up, I like to re-visit the:
Pass memory ranges via e820 tables to crash kernel
work.
These are some cleanup patches on code I stumbled over while looking at
this. It would be great if these can get applied, so that my local branch
is in sync with mainline. I then like to proceed with further cleanups and
finally get to the point where a clean, split up in small patches submission
to implement above is possible.

Thanks,

       Thomas