net: ipv6: Standardize prefixes for message logging

Add #define pr_fmt(fmt) as appropriate.

Add "IPv6: " to appropriate files.

Convert printk(KERN_<LEVEL> to pr_<level> (but not KERN_DEBUG).
Standardize on "%s: " not "%s(): " when emitting __func__.
Use "%s: ", __func__ instead of embedding function name.
Coalesce formats, align arguments.

ADDRCONF output is now prefixed with "IPv6: "

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index a36a097..6041571 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -17,6 +17,8 @@
  * Fred Templin <fred.l.templin@boeing.com>:	isatap support
  */
 
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
 #include <linux/module.h>
 #include <linux/capability.h>
 #include <linux/errno.h>
@@ -1301,7 +1303,7 @@
 {
 	int err;
 
-	printk(KERN_INFO "IPv6 over IPv4 tunneling driver\n");
+	pr_info("IPv6 over IPv4 tunneling driver\n");
 
 	err = register_pernet_device(&sit_net_ops);
 	if (err < 0)
@@ -1309,7 +1311,7 @@
 	err = xfrm4_tunnel_register(&sit_handler, AF_INET6);
 	if (err < 0) {
 		unregister_pernet_device(&sit_net_ops);
-		printk(KERN_INFO "sit init: Can't add protocol\n");
+		pr_info("%s: can't add protocol\n", __func__);
 	}
 	return err;
 }