Revert "lockd: Show pid of lockd for remote locks"

This reverts most of commit b8eee0e9 ("lockd: Show pid of lockd for
remote locks"), which caused remote locks to not be differentiated between
remote processes for NLM.

We retain the fixup for setting the client's fl_pid to a negative value.

Fixes: b8eee0e9

 ("lockd: Show pid of lockd for remote locks")
Cc: stable@vger.kernel.org

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
Reviewed-by: XueWei Zhang <xueweiz@google.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>