staging: wfx: fix double free

In case of error in wfx_probe(), wdev->hw is freed. Since an error
occurred, wfx_free_common() is called, then wdev->hw is freed again.
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Reviewed-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Fixes: 4033714d ("staging: wfx: fix init/remove vs IRQ race")
Link: https://lore.kernel.org/r/20200505123757.39506-4-Jerome.Pouiller@silabs.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/main.c

@@ -469,7 +469,6 @@ int wfx_probe(struct wfx_dev *wdev)
 
 err2:
 	ieee80211_unregister_hw(wdev->hw);
-	ieee80211_free_hw(wdev->hw);
 err1:
 	wfx_bh_unregister(wdev);
 	return err;