drm/panfrost: Check for error num after setting mask

Because of the possible failure of the dma_supported(), the
dma_set_mask_and_coherent() may return error num.
Therefore, it should be better to check it and return the error if
fails.

Fixes: f3ba9122 ("drm/panfrost: Add initial panfrost driver")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
[Steve: fix Fixes: line]
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220106030326.2620942-1-jiasheng@iscas.ac.cn

drivers/gpu/drm/panfrost/panfrost_gpu.c

@@ -360,8 +360,11 @@ int panfrost_gpu_init(struct panfrost_device *pfdev)
 
 	panfrost_gpu_init_features(pfdev);
 
-	dma_set_mask_and_coherent(pfdev->dev,
+	err = dma_set_mask_and_coherent(pfdev->dev,
 		DMA_BIT_MASK(FIELD_GET(0xff00, pfdev->features.mmu_features)));
+	if (err)
+		return err;
+
 	dma_set_max_seg_size(pfdev->dev, UINT_MAX);
 
 	irq = platform_get_irq_byname(to_platform_device(pfdev->dev), "gpu");