[ Upstream commit 57a25a5f ]

`best_clock` is an object that may be sent out. Object `clock`
contains uninitialized bytes that are copied to `best_clock`,
which leads to memory disclosure and information leak.
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20191018042953.31099-1-kjlu@umn.eduSigned-off-by: Sasha Levin <sashal@kernel.org>