Replace dev_kfree_skb with dev_consume_skb_any in sc92031_start_xmit
that can be called in hard irq and other contexts.

Using dev_consume_skb_any preserves the current semantics (as
dev_kfree_skb is just consume_skb) and since packet drops
are rare is usually accurate.
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>