against 2.6.12-rc4

This patch removes O(n^2) super block loops
in sync_inodes(), sync_filesystems() etc. in favour
of using __put_super_and_need_restart() which
I introduced earlier. We faced a noticably long freezes on sb
syncing when there are thousands of super blocks in the system.

The patch was heavilly tested on 2.6.8 during 3 months,
this forward-ported version boots and works ok as well.

Signed-Off-By: Kirill Korotaev <dev@sw.ru>