LU-14541 llite: avoid stale data reading

LU-14541 llite: avoid stale data reading

remove_mapping() can prohibit to kill page from page cache due page
refcount!=2, in vvp_page_delete() clear uptodate flag in case
stale data reading later.

Lustre-change: https://review.whamcloud.com/43476
Lustre-commit: TBD (from e6033b193e8d35e689b7c2860374c8b2d2b7a5ee)

Signed-off-by: Wang Shilong <wshilong@ddn.com>
Change-Id: I322debec951b1a342246475456c0f40e10b0e578
Reviewed-on: https://review.whamcloud.com/44291
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>