nilfs2: add a print message after loading nilfs2

Printing a message after loading a file system is a practice. Add this to
provide a better user-friendly experience.

Signed-off-by: Li Hong <lihong.hi@gmail.com>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c
index 5a08c82..a512c3b 100644
--- a/fs/nilfs2/super.c
+++ b/fs/nilfs2/super.c
@@ -1190,6 +1190,7 @@
 	if (err)
 		goto free_cachep;
 
+	printk(KERN_INFO "NILFS version 2 loaded\n");
 	return 0;
 
 free_cachep: