Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 mm fixlet from Ingo Molnar:
 "One cleanup that documents a particular detail in init_mem_mapping()"

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Add 'step_size' comments to init_mem_mapping()