idsn: fix wrong skb_put() used

in my commit b952f4df,
-	*(u8 *)skb_put(skb_out, 1) = (u8)(accm >> 24);	\
+	skb_put(skb_out, (u8)(accm >> 24));	\
it should skb_put_u8()

Fixes: b952f4df ("net: manual clean code which call skb_put_[data:zero])")
Signed-off-by: yuan linyu <Linyu.Yuan@alcatel-sbell.com.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>