[PATCH] compat_sys_nfsservctl(): handle errors correctly

Correct some error handling on the compat version of the nfsservctl()
system.  It was detecting errors while copying in the arguments from user
space, but then attempting to use the arguments anyway.  This didn't seem
so good.

Signed-off-by: Peter Staubach <staubach@redhat.com>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>