remove remaining references to nfsservctl

These were missed in commit f5b94099 "All Arch: remove linkage
for sys_nfsservctl system call" due to them having no sys_ prefix
(presumably).

Cc: NeilBrown <neilb@suse.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: James Bottomley <James.Bottomley@hansenpartnership.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>