[PATCH] reiserfs: fix key decrementing

This patch fixes a bug in function decrementing a key of stat data item.

Offset of reiserfs keys are compared as signed values.  To set key offset
to maximal possible value maximal signed value has to be used.

This bug is responsible for severe reiserfs filesystem corruption which
shows itself as warning vs-13060.  reiserfsck fixes this corruption by
filesystem tree rebuilding.

Signed-off-by: Vladimir Saveliev <vs@namesys.com>
Cc: <reiserfs-dev@namesys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>