Correct K3 set_ant

As the K3 does not return a response to the AN? set command, direct the
backend to use kenwood_set_ant_no_ack() instead.  Thanks to Alexander
Sack, KC2ZSX for catching this.
(cherry picked from commit 3757b9af27)

kenwood/k3.c

@@ -213,7 +213,7 @@ const struct rig_caps k3_caps = {
 	.get_trn =		kenwood_get_trn,
 	.set_powerstat =	kenwood_set_powerstat,
 	.get_powerstat =	kenwood_get_powerstat,
-	.set_ant =		kenwood_set_ant,
+	.set_ant =		kenwood_set_ant_no_ack,
 	.get_ant =		kenwood_get_ant,
 	.send_morse =		kenwood_send_morse,