seq_file: use proc_create() in documentation

Using create_proc_entry() + ->proc_fops assignment is racy because
->proc_fops will be NULL for some time, use proc_create() to avoid race.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Documentation/filesystems/seq_file.txt

@@ -248,9 +248,7 @@ code, that is done in the initialization code in the usual way:
 	{
 	        struct proc_dir_entry *entry;
 
-	        entry = create_proc_entry("sequence", 0, NULL);
-	        if (entry)
-	                entry->proc_fops = &ct_file_ops;
+	        proc_create("sequence", 0, NULL, &ct_file_ops);
 	        return 0;
 	}