Revert "UPSTREAM: vfs: fix dentry RCU to refcounting possibly sleeping dput()"

This reverts commit 49aff5f4d470b483d947def3ab97a2252c04a62b.

This commit seems to cause an intermittent refcounting bug in the
mount cache that leads to a crash in namespace_unlock, so let's revert
it to improve stability.

BUG=chromium:871915
TEST=manual, run crash reporter in a loop, no kernel crashes

Signed-off-by: Sonny Rao <sonnyrao@chromium.org>

Change-Id: Iea98af7160210a5340269cac3578217d4d2b9426
Reviewed-on: https://chromium-review.googlesource.com/1460484
Commit-Ready: Sonny Rao <sonnyrao@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Brian Norris <briannorris@chromium.org>
(cherry picked from commit bab122bd099ef0001b3a411b51427382a4ce083a)
Reviewed-on: https://chromium-review.googlesource.com/1551500
Tested-by: Sonny Rao <sonnyrao@chromium.org>
1 file changed