mac802154: Use pr_err(...) rather than printk(KERN_ERR ...)

This change is inspired by checkpatch.
Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/mac802154/ieee802154_dev.c

@@ -174,8 +174,7 @@ ieee802154_alloc_device(size_t priv_data_len, struct ieee802154_ops *ops)
 
 	if (!ops || !ops->xmit || !ops->ed || !ops->start ||
 	    !ops->stop || !ops->set_channel) {
-		printk(KERN_ERR
-		       "undefined IEEE802.15.4 device operations\n");
+		pr_err("undefined IEEE802.15.4 device operations\n");
 		return NULL;
 	}
 
@@ -201,8 +200,7 @@ ieee802154_alloc_device(size_t priv_data_len, struct ieee802154_ops *ops)
 
 	phy = wpan_phy_alloc(priv_size);
 	if (!phy) {
-		printk(KERN_ERR
-		       "failure to allocate master IEEE802.15.4 device\n");
+		pr_err("failure to allocate master IEEE802.15.4 device\n");
 		return NULL;
 	}