net: Convert printks to pr_<level>

Use a more current kernel messaging style.

Convert a printk block to print_hex_dump.
Coalesce formats, align arguments.
Use %s, __func__ instead of embedding function names.

Some messages that were prefixed with <foo>_close are
now prefixed with <foo>_fini.  Some ah4 and esp messages
are now not prefixed with "ip ".

The intent of this patch is to later add something like
  #define pr_fmt(fmt) "IPv4: " fmt.
to standardize the output messages.

Text size is trivially reduced. (x86-32 allyesconfig)

$ size net/ipv4/built-in.o*
   text	   data	    bss	    dec	    hex	filename
 887888	  31558	 249696	1169142	 11d6f6	net/ipv4/built-in.o.new
 887934	  31558	 249800	1169292	 11d78c	net/ipv4/built-in.o.old

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/tunnel4.c b/net/ipv4/tunnel4.c
index 0177598..0d01718 100644
--- a/net/ipv4/tunnel4.c
+++ b/net/ipv4/tunnel4.c
@@ -164,12 +164,12 @@
 static int __init tunnel4_init(void)
 {
 	if (inet_add_protocol(&tunnel4_protocol, IPPROTO_IPIP)) {
-		printk(KERN_ERR "tunnel4 init: can't add protocol\n");
+		pr_err("%s: can't add protocol\n", __func__);
 		return -EAGAIN;
 	}
 #if IS_ENABLED(CONFIG_IPV6)
 	if (inet_add_protocol(&tunnel64_protocol, IPPROTO_IPV6)) {
-		printk(KERN_ERR "tunnel64 init: can't add protocol\n");
+		pr_err("tunnel64 init: can't add protocol\n");
 		inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP);
 		return -EAGAIN;
 	}
@@ -181,10 +181,10 @@
 {
 #if IS_ENABLED(CONFIG_IPV6)
 	if (inet_del_protocol(&tunnel64_protocol, IPPROTO_IPV6))
-		printk(KERN_ERR "tunnel64 close: can't remove protocol\n");
+		pr_err("tunnel64 close: can't remove protocol\n");
 #endif
 	if (inet_del_protocol(&tunnel4_protocol, IPPROTO_IPIP))
-		printk(KERN_ERR "tunnel4 close: can't remove protocol\n");
+		pr_err("tunnel4 close: can't remove protocol\n");
 }
 
 module_init(tunnel4_init);