nfs: emit a fsnotify_nameremove call in sillyrename codepath

If a file is sillyrenamed, then the generic vfs_unlink code will skip
emitting fsnotify events for it.

This patch has the sillyrename code do that instead.

In truth this is a little bit odd since we aren't actually removing the
dentry per-se, but renaming it. Still, this is probably the right thing
to do since it's what userland apps expect to see when an unlink()
occurs or some file is renamed on top of the dentry.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Tested-by: Anna Schumaker <Anna.Schumaker@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>