dma-buf: fix reservation_object_wait_timeout_rcu once more v2

dma-buf: fix reservation_object_wait_timeout_rcu once more v2

BugLink: http://bugs.launchpad.net/bugs/1751131
commit 5bffee867df7494ecd32c1e6ec4e8fc934c521b7 upstream.

We need to set shared_count even if we already have a fence to wait for.

v2: init i to -1 as well

Signed-off-by: Christian König <christian.koenig@amd.com>
Cc: stable@vger.kernel.org
Tested-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180122200003.6665-1-christian.koenig@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>