net: sched : Remove unnecessary cast in kfree

Remove unnecassary casts in the argument to kfree.
Signed-off-by: NXu Wang <vulab@iscas.ac.cn>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sched/em_ipt.c

@@ -199,7 +199,7 @@ static void em_ipt_destroy(struct tcf_ematch *em)
 		im->match->destroy(&par);
 	}
 	module_put(im->match->me);
-	kfree((void *)im);
+	kfree(im);
 }
 
 static int em_ipt_match(struct sk_buff *skb, struct tcf_ematch *em,