[PATCH] reiserfs: do not check if unsigned < 0

This patch fixes bugs in reiserfs where unsigned integers were checked
whether they are less then 0.

Signed-off-by: Vladimir V. Saveliev <vs@namesys.com>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Hans Reiser <reiser@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>