m68knommu: show KiB rather than pages in "Freeing initrd memory:" message

Fix "Freeing initrd memory:" message m68knommu to show kilobytes as
claimed rather than number of pages.

Signed-off-by: Lennart Sorensen <lsorense@csclub.uwaterloo.ca>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>