binfmt_elf_fdpic: Fix build breakage introduced by coredump changes.

Commit f6151dfe introduces build
breakage, so this patch fixes it together with some printk formatting
cleanup.

Signed-off-by: Daisuke HATAYAMA <d.hatayama@jp.fujitsu.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>