dma-fence: Clear fence->status during dma_fence_init()

commit 83dd1376fd upstream.

As the fence->status is an optional field that may be set before
dma_fence_signal() is called to convey that the fence completed with an
error, we have to ensure that it is always set to zero on initialisation
so that the typical use (i.e. unset) always flags a successful completion.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Sumit Semwal <sumit.semwal@linaro.org>
Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Link: http://patchwork.freedesktop.org/patch/msgid/20170104141222.6992-1-chris@chris-wilson.co.uk
[s/dma_fence/fence/g - gregkh]
Cc: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/dma-buf/fence.c

@@ -526,6 +526,7 @@ fence_init(struct fence *fence, const struct fence_ops *ops,
 	fence->context = context;
 	fence->seqno = seqno;
 	fence->flags = 0UL;
+	fence->status = 0;
 
 	trace_fence_init(fence);
 }