proc: convert /proc/$PID/hardwall to seq_file interface

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --cc arch/tile/include/asm/hardwall.h
Simple merge

diff --cc arch/tile/kernel/hardwall.c
Simple merge

diff --cc fs/proc/base.c
Simple merge