ax25: Fix the build when CONFIG_INET is disabled

ax25: Fix the build when CONFIG_INET is disabled

>
> >> net/ax25/ax25_ip.c:225:26: error: unknown type name 'sturct'
>     netdev_tx_t ax25_ip_xmit(sturct sk_buff *skb)
>                              ^
>
> vim +/sturct +225 net/ax25/ax25_ip.c
>
>    219				    unsigned short type, const void *daddr,
>    220				    const void *saddr, unsigned int len)
>    221	{
>    222		return -AX25_HEADER_LEN;
>    223	}
>    224
>  > 225	netdev_tx_t ax25_ip_xmit(sturct sk_buff *skb)
>    226	{
>    227		kfree_skb(skb);
>    228		return NETDEV_TX_OK;

Ooops I misspelled struct...

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David S. Miller <davem@davemloft.net>