include/linux: fix excess fence.h kernel-doc notation

Fix excess fields in kernel-doc notation in <linux/fence.h>
after some struct fields were removed.

Fixes these kernel-doc warnings:
..//include/linux/fence.h:85: warning: Excess struct/union/enum/typedef member 'child_list' description in 'fence'
..//include/linux/fence.h:85: warning: Excess struct/union/enum/typedef member 'active_list' description in 'fence'

Fixes: 0431b906 ("staging/android: bring struct sync_pt back")

Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Luis de Bethencourt <luisbg@osg.samsung.com>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/fence.h

@@ -49,8 +49,6 @@ struct fence_cb;
  * @timestamp: Timestamp when the fence was signaled.
  * @status: Optional, only valid if < 0, must be set before calling
  * fence_signal, indicates that the fence has completed with an error.
- * @child_list: list of children fences
- * @active_list: list of active fences
  *
  * the flags member must be manipulated and read using the appropriate
  * atomic ops (bit_*), so taking the spinlock will not be needed most