NFSv2/v3: Fix up a race in the case where the user presses ^C while a
   process is in the middle of setting up a posix lock. In case the
   server registered our lock, we need to make sure that it gets
   cleaned up during the resulting file close().
Signed-off-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>