The patches from Eric, that add support for so called ctl_paths
has recently being accepted, so I hope we can start using this
very useful feature.

To begin with, I switched the core kernel code to use the paths.
The rest code to be patched (after this set) will be:
 * arch-specifi,
 * some filesystems,
 * networking.

After this set the total vmlinux size decrease is ~500 bytes:

add/remove: 5/6 grow/shrink: 5/1 up/down: 121/-616 (-495)
function                                     old     new   delta
mq_sysctl_path                                 -      24     +24
fs_quota_path                                  -      24     +24
uts_root_path                                  -      16     +16
sd_ctl_path                                    -      16     +16
ipc_root_path                                  -      16     +16
utsname_sysctl_init                           13      18      +5
register_sched_domain_sysctl                 762     767      +5
ipc_sysctl_init                               13      18      +5
init_mqueue_fs                               165     170      +5
dquot_init                                   191     196      +5
uts_root_table                                88       -     -88
sys_table                                     88       -     -88
sd_ctl_root                                   88       -     -88
mq_sysctl_root                                88       -     -88
mq_sysctl_dir                                 88       -     -88
ipc_root_table                                88       -     -88
fs_table                                     792     704     -88

The set is prepared to fit the 2.6.24-rc3-mm2 kernel with Eric's
patches concerning sysctls.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>