Make alloc_page_buffers() initialise buffer_heads using init_buffer(),

like other routines here, to ensure buffers are correctly initialised
with respect to b_private/b_end_io.  Fixes an odd interaction between
XFS and reiserfs.
Signed-off-by: Nathan Scott <nathans@sgi.com>

fs/buffer.c

@@ -1027,7 +1027,7 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,
 		/* Link the buffer to its page */
 		set_bh_page(bh, page, offset);
 
-		bh->b_end_io = NULL;
+		init_buffer(bh, NULL, NULL);
 	}
 	return head;
 /*