docbook: add pipes, other fixes

Fix some typos in pipe.c and splice.c.
Add pipes API to kernel-api.tmpl.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/fs/pipe.c b/fs/pipe.c
index d007830..6b3d91a 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -255,7 +255,7 @@
 
 /**
  * generic_pipe_buf_confirm - verify contents of the pipe buffer
- * @pipe:	the pipe that the buffer belongs to
+ * @info:	the pipe that the buffer belongs to
  * @buf:	the buffer to confirm
  *
  * Description: