cfg80211: add missing break in cfg80211_get_chan_state()

Improve readability of the function by adding the break,
there's no functional impact but it's confusing to fall
through.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/wireless/chan.c b/net/wireless/chan.c
index 96c9780..3b6daf8 100644
--- a/net/wireless/chan.c
+++ b/net/wireless/chan.c
@@ -599,6 +599,7 @@
 				  : CHAN_MODE_EXCLUSIVE;
 			return;
 		}
+		break;
 	case NL80211_IFTYPE_STATION:
 	case NL80211_IFTYPE_P2P_CLIENT:
 		if (wdev->current_bss) {