zd1211rw: stop beacons on remove_interface

If a mesh or ad-hoc interface is brought up and later it is replaced
by managed interface, the managed interface will keep transmitting
the beacons that were configured for the former interface. This patch
fixes that behaviour.

Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/zd1211rw/zd_mac.c b/drivers/net/wireless/zd1211rw/zd_mac.c
index 418606a..694e95d 100644
--- a/drivers/net/wireless/zd1211rw/zd_mac.c
+++ b/drivers/net/wireless/zd1211rw/zd_mac.c
@@ -765,6 +765,7 @@
 {
 	struct zd_mac *mac = zd_hw_mac(hw);
 	mac->type = IEEE80211_IF_TYPE_INVALID;
+	zd_set_beacon_interval(&mac->chip, 0);
 	zd_write_mac_addr(&mac->chip, NULL);
 }