Revert "ext4: make dioread_nolock the default"

This reverts commit 1e82b7ed214e1c924ab94521e25a179eeb4e80e6.

BUG=b/156407116
TESTED=ran xfstests smoke to verify no regressions

Change-Id: I5c12c3c8a8ad6301a64753e59b15193275dee04c
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/1900
Reviewed-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
(cherry picked from commit f8649a7408c63f53937e33b0e8379679b0434849)
Reviewed-on: https://cos-review.googlesource.com/c/third_party/kernel/+/1940
Reviewed-by: Roy Yang <royyang@google.com>