mwifiex: don't leak 'chan_stats' on reset

'chan_stats' is (re)allocated in _mwifiex_fw_dpc() ->
mwifiex_init_channel_scan_gap(), which is called whenever the device is
initialized -- at probe or at reset.

But we only free it in we completely unregister the adapter, meaning we
leak a copy of it during every reset.

Let's free it in the shutdown / removal paths instead (and in the
error-handling path), to avoid the leak.

Ideally, we can eventually unify much of mwifiex_shutdown_sw() and
mwifiex_remove_card() (way too much copy-and-paste) to reduce the burden
on bugfixes like this. But that's work for tomorrow.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/main.c

@@ -149,7 +149,6 @@ static int mwifiex_unregister(struct mwifiex_adapter *adapter)
 
 	kfree(adapter->regd);
 
-	vfree(adapter->chan_stats);
 	kfree(adapter);
 	return 0;
 }
@@ -633,6 +632,7 @@ static int _mwifiex_fw_dpc(const struct firmware *firmware, void *context)
 	goto done;
 
 err_add_intf:
+	vfree(adapter->chan_stats);
 	wiphy_unregister(adapter->wiphy);
 	wiphy_free(adapter->wiphy);
 err_init_fw:
@@ -1417,6 +1417,7 @@ mwifiex_shutdown_sw(struct mwifiex_adapter *adapter)
 			mwifiex_del_virtual_intf(adapter->wiphy, &priv->wdev);
 		rtnl_unlock();
 	}
+	vfree(adapter->chan_stats);
 
 	mwifiex_dbg(adapter, INFO, "%s, successful\n", __func__);
 exit_return:
@@ -1726,6 +1727,7 @@ int mwifiex_remove_card(struct mwifiex_adapter *adapter)
 			mwifiex_del_virtual_intf(adapter->wiphy, &priv->wdev);
 		rtnl_unlock();
 	}
+	vfree(adapter->chan_stats);
 
 	wiphy_unregister(adapter->wiphy);
 	wiphy_free(adapter->wiphy);