libceph: don't omit used_replica in target_copy()

Currently target_copy() is used only for sending linger pings, so
this doesn't come up, but generally omitting used_replica can hang
the client as we wouldn't notice the acting set change (legacy_change
in calc_target()) or trigger a warning in handle_reply().

Fixes: 117d96a0 ("libceph: support for balanced and localized reads")
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

net/ceph/osd_client.c

@@ -448,6 +448,7 @@ static void target_copy(struct ceph_osd_request_target *dest,
 	dest->recovery_deletes = src->recovery_deletes;
 
 	dest->flags = src->flags;
+	dest->used_replica = src->used_replica;
 	dest->paused = src->paused;
 
 	dest->epoch = src->epoch;