drm/ttm: fix ttm_execbuf_util.h kernel-doc warnings

Fix some formatting errors and excess documentation.

Cc: Christian Koenig <[e-mail]>
Cc: Huang Rui <[e-mail]>
Acked-by: Thomas Zimmermann <[e-mail]>
Reviewed-by: Christian König <[e-mail]>
Signed-off-by: Jani Nikula <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/b0f[e-mail]

include/drm/ttm/ttm_execbuf_util.h

···
 };
 
 /**
- * function ttm_eu_backoff_reservation
+ * ttm_eu_backoff_reservation
  *
  * @ticket:   ww_acquire_ctx from reserve call
  * @list:     thread private list of ttm_validate_buffer structs.
···
 				struct list_head *list);
 
 /**
- * function ttm_eu_reserve_buffers
+ * ttm_eu_reserve_buffers
  *
  * @ticket:  [out] ww_acquire_ctx filled in by call, or NULL if only
  *           non-blocking reserves should be tried.
  * @list:    thread private list of ttm_validate_buffer structs.
  * @intr:    should the wait be interruptible
  * @dups:    [out] optional list of duplicates.
- * @del_lru: true if BOs should be removed from the LRU.
  *
  * Tries to reserve bos pointed to by the list entries for validation.
  * If the function returns 0, all buffers are marked as "unfenced",
···
 			   struct list_head *dups);
 
 /**
- * function ttm_eu_fence_buffer_objects.
+ * ttm_eu_fence_buffer_objects
  *
  * @ticket:      ww_acquire_ctx from reserve call
  * @list:        thread private list of ttm_validate_buffer structs.