docs: fix various Documentation/ paths in header files

Fix various Documentation/ paths in include/linux/.

Signed-off-by: Randy Dunlap <[e-mail]>
Reviewed-by: Jesper Juhl <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

include/linux/configfs.h

···
  *
  * configfs Copyright (C) 2005 Oracle.  All rights reserved.
  *
- * Please read Documentation/filesystems/configfs.txt before using the
- * configfs interface, ESPECIALLY the parts about reference counts and
+ * Please read Documentation/filesystems/configfs/configfs.txt before using
+ * the configfs interface, ESPECIALLY the parts about reference counts and
  * item destructors.
  */
 

include/linux/debugfs.h

···
  *	2 as published by the Free Software Foundation.
  *
  *  debugfs is for people to use instead of /proc or /sys.
- *  See Documentation/DocBook/kernel-api for more details.
+ *  See Documentation/DocBook/filesystems for more details.
  */
 
 #ifndef _DEBUGFS_H_

include/linux/relay.h

···
 	 * cause relay_open() to create a single global buffer rather
 	 * than the default set of per-cpu buffers.
 	 *
-	 * See Documentation/filesystems/relayfs.txt for more info.
+	 * See Documentation/filesystems/relay.txt for more info.
 	 */
 	struct dentry *(*create_buf_file)(const char *filename,
 					  struct dentry *parent,

include/linux/tracepoint.h

···
 /*
  * Kernel Tracepoint API.
  *
- * See Documentation/tracepoint.txt.
+ * See Documentation/trace/tracepoints.txt.
  *
  * (C) Copyright 2008 Mathieu Desnoyers <[e-mail]>
  *