sch_dsmark: Fix uninitialized variable warning.

We still need to initialize err to -EINVAL for
the case where 'opt' is NULL in dsmark_init().

Fixes: 6529eaba33f0 ("net: sched: introduce tcf block infractructure")
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/sch_dsmark.c

@@ -333,7 +333,7 @@ static int dsmark_init(struct Qdisc *sch, struct nlattr *opt)
 {
 	struct dsmark_qdisc_data *p = qdisc_priv(sch);
 	struct nlattr *tb[TCA_DSMARK_MAX + 1];
-	int err;
+	int err = -EINVAL;
 	u32 default_index = NO_DEFAULT_INDEX;
 	u16 indices;
 	int i;