Revert "LU-14541 llite: Check vmpage in releasepage"

Revert "LU-14541 llite: Check vmpage in releasepage"

This reverts commit c524079f4f59a39b99467d9868ee4aafdcf033e9,
because it breaks releasepage for Lustre and does not
completely fix the data consistency issue in LU-14541.

Breaking releasepage matters because it prevents direct I/O
from working if there is page cache data present, and
because it causes similar issues with GDS, which must be
able to flush page cache pages before doing I/O.

With patches:
"LU-16160 llite: SIGBUS is possible on a race with page reclaim"/
d9c23a7934747eb19e23470b30806482a1aa60f8
and
"LU-14541 llite: Check for page deletion after fault"/
19678e30147f50f813e72e8216cfb0453fe0ca6e
LU-14541 is fully resolved, so we can revert this patch.

Lustre-change: https://review.whamcloud.com/49654
Lustre-commit: e3cfb688ed7116a57b2c7f89a3e4f28291a0b69f

Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: I613bdb4f27161ffc3638d1d8ea38827af5a7bd47
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/50304
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>