staging: wfx: Fix a memory leak in 'wfx_upload_beacon'

The current code is a no-op, because all it can do is 'dev_kfree_skb(NULL)'
Remove the test before 'dev_kfree_skb()'
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/20191102155945.20205-1-christophe.jaillet@wanadoo.frSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/wfx/sta.c

@@ -906,8 +906,7 @@ static int wfx_upload_beacon(struct wfx_vif *wvif)
 	wfx_fwd_probe_req(wvif, false);
 
 done:
-	if (!skb)
-		dev_kfree_skb(skb);
+	dev_kfree_skb(skb);
 	return ret;
 }