core: remove pointless conditional before kfree()

Remove pointless conditional before kfree().

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 244ca56..d9d5160 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -261,8 +261,7 @@
 	ret = 0;
 
 err_out:
-	if (rule_buf)
-		kfree(rule_buf);
+	kfree(rule_buf);
 
 	return ret;
 }