dma-fence: Don't BUG_ON when not absolutely needed

It makes debugging a massive pain.

Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: linux-media@vger.kernel.org
Cc: linaro-mm-sig@lists.linaro.org
Reviewed-by: Lucas Stach <l.stach@pengutronix.de>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170720125107.26693-1-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/dma-buf/dma-fence.c

@@ -48,7 +48,7 @@ static atomic64_t dma_fence_context_counter = ATOMIC64_INIT(0);
  */
 u64 dma_fence_context_alloc(unsigned num)
 {
-	BUG_ON(!num);
+	WARN_ON(!num);
 	return atomic64_add_return(num, &dma_fence_context_counter) - num;
 }
 EXPORT_SYMBOL(dma_fence_context_alloc);
@@ -177,7 +177,7 @@ void dma_fence_release(struct kref *kref)
 
 	trace_dma_fence_destroy(fence);
 
-	BUG_ON(!list_empty(&fence->cb_list));
+	WARN_ON(!list_empty(&fence->cb_list));
 
 	if (fence->ops->release)
 		fence->ops->release(fence);

include/linux/dma-fence.h

@@ -429,8 +429,8 @@ int dma_fence_get_status(struct dma_fence *fence);
 static inline void dma_fence_set_error(struct dma_fence *fence,
 				       int error)
 {
-	BUG_ON(test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags));
-	BUG_ON(error >= 0 || error < -MAX_ERRNO);
+	WARN_ON(test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &fence->flags));
+	WARN_ON(error >= 0 || error < -MAX_ERRNO);
 
 	fence->error = error;
 }