inotify_system_nodel.c: make it a static symlink

inotify_system_nodel.c is supposed to be a symlink to inotify_system.c,
but somehow the file was committed. This, together with the statement
in Makefile to recreate the file, lead to replacing the file with a
symlink during make.

Remove the file, add the symlink, and remove the Makefile rule.

PS yes, I have checked the files are identical.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
Signed-off-by: Andrei Vagin <avagin@virtuozzo.com>