LU-196 set debug_mb size for every node

commit 01e1bdcec4af985791b40e1fbfaa77a2d5427fce
Date: Mon Feb 14 20:25:35 2011 +0300

b=19944 adjust debug size to be -gt num_possible_cpus()

a=Landen <zhiyong.tian@oracle.com>
i=Elena.Gryaznova

Change-Id: Idc8c3d2db243c5ddd0ba95ef1be4680c4af9c411
Signed-off-by: YangSheng <ys@whamcloud.com>
Signed-off-by: Yu Jian <yujian@whamcloud.com>
Reviewed-on: http://review.whamcloud.com/407
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>