scripts/namespace.pl: some bug fixes

1. Teach namespace.pl to understand "V" and "v"
2. cond_syscalls are moved into kernel/sys_ni.c

Signed-off-by: Amerigo Wang <amwang@redhat.com>
Cc: Stephen Hemminger <shemminger@vyatta.com>
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>