atm: clean up vcc_seq_next()

It's confusing to call PTR_ERR(v).  The PTR_ERR() function is basically
a fancy cast to long so it makes you wonder, was IS_ERR() intended?  But
that doesn't make sense because vcc_walk() doesn't return error
pointers.

This patch doesn't affect runtime, it's just a cleanup.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/atm/proc.c

@@ -134,7 +134,8 @@ static void vcc_seq_stop(struct seq_file *seq, void *v)
 static void *vcc_seq_next(struct seq_file *seq, void *v, loff_t *pos)
 {
 	v = vcc_walk(seq, 1);
-	*pos += !!PTR_ERR(v);
+	if (v)
+		(*pos)++;
 	return v;
 }