mac80211: Deinline drv_switch_vif_chanctx()

With this .config: http://busybox.net/~vda/kernel_config_ALLYES_Os,
after deinlining the function size is 821 bytes and there are
2 callsites, reducing code size by about 800 bytes.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
CC: Johannes Berg <johannes.berg@intel.com>
CC: John Linville <linville@tuxdriver.com>
CC: Michal Kazior <michal.kazior@tieto.com>
CC: linux-wireless@vger.kernel.org
CC: linux-kernel@vger.kernel.org
[adjust code-style a bit]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
diff --git a/net/mac80211/driver-ops.c b/net/mac80211/driver-ops.c
index b284e6e..1a720e8 100644
--- a/net/mac80211/driver-ops.c
+++ b/net/mac80211/driver-ops.c
@@ -138,3 +138,54 @@
 	trace_drv_return_int(local, ret);
 	return ret;
 }
+
+int drv_switch_vif_chanctx(struct ieee80211_local *local,
+			   struct ieee80211_vif_chanctx_switch *vifs,
+			   int n_vifs, enum ieee80211_chanctx_switch_mode mode)
+{
+	int ret = 0;
+	int i;
+
+	if (!local->ops->switch_vif_chanctx)
+		return -EOPNOTSUPP;
+
+	for (i = 0; i < n_vifs; i++) {
+		struct ieee80211_chanctx *new_ctx =
+			container_of(vifs[i].new_ctx,
+				     struct ieee80211_chanctx,
+				     conf);
+		struct ieee80211_chanctx *old_ctx =
+			container_of(vifs[i].old_ctx,
+				     struct ieee80211_chanctx,
+				     conf);
+
+		WARN_ON_ONCE(!old_ctx->driver_present);
+		WARN_ON_ONCE((mode == CHANCTX_SWMODE_SWAP_CONTEXTS &&
+			      new_ctx->driver_present) ||
+			     (mode == CHANCTX_SWMODE_REASSIGN_VIF &&
+			      !new_ctx->driver_present));
+	}
+
+	trace_drv_switch_vif_chanctx(local, vifs, n_vifs, mode);
+	ret = local->ops->switch_vif_chanctx(&local->hw,
+					     vifs, n_vifs, mode);
+	trace_drv_return_int(local, ret);
+
+	if (!ret && mode == CHANCTX_SWMODE_SWAP_CONTEXTS) {
+		for (i = 0; i < n_vifs; i++) {
+			struct ieee80211_chanctx *new_ctx =
+				container_of(vifs[i].new_ctx,
+					     struct ieee80211_chanctx,
+					     conf);
+			struct ieee80211_chanctx *old_ctx =
+				container_of(vifs[i].old_ctx,
+					     struct ieee80211_chanctx,
+					     conf);
+
+			new_ctx->driver_present = true;
+			old_ctx->driver_present = false;
+		}
+	}
+
+	return ret;
+}