mysys/array.c:
  Rewrite functions comments
mysys/checksum.c:
  Rewrite function comment
  Style cleanup
mysys/mulalloc.c:
  Rewrite function comment
mysys/my_chsize.c:
  Rewrite function comment
mysys/my_error.c:
  Rewrite comments
mysys/my_once.c:
  Rewrite comments
mysys/my_div.c:
  Rewrite comments
mysys/my_open.c:
  Rewrite comments