drm/amd/amdgpu: fix over-bound accessing in amdgpu_cs_wait_any_fence

Fixes an oops in amdgpu_cs_wait_any_fence.
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Chunming Zhou <david1.zhou@amd.com>
Signed-off-by: Roger He <Hongbo.He@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

@@ -1498,7 +1498,7 @@ static int amdgpu_cs_wait_any_fence(struct amdgpu_device *adev,
 	wait->out.status = (r > 0);
 	wait->out.first_signaled = first;
 
-	if (array[first])
+	if (first < fence_count && array[first])
 		r = array[first]->error;
 	else
 		r = 0;