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.fr


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>