[PATCH] vt: fix comments to not refer to kill_proc

The code has been fixed to use kill_pid instead of kill_proc fix the
comments as well.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>