media: s5p-mfc: fix incorrect bus assignment in virtual child device

[ Upstream commit 1e0d0a5fd38192f23304ea2fc2b531fea7c74247 ]

Virtual MFC codec's child devices must not be assigned to platform bus,
because they are allocated as raw 'struct device' and don't have the
corresponding 'platform' part. This fixes NULL pointer access revealed
recently by commit a66d972465d1 ("devres: Align data[] to
ARCH_KMALLOC_MINALIGN").

Fixes: c79667dd ("media: s5p-mfc: replace custom reserved memory handling code with generic one")
Reported-by: NPaweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Signed-off-by: NMarek Szyprowski <m.szyprowski@samsung.com>
Tested-by: NPaweł Chmiel <pawel.mikolaj.chmiel@gmail.com>
Signed-off-by: NMauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/media/platform/s5p-mfc/s5p_mfc.c

@@ -1089,7 +1089,6 @@ static struct device *s5p_mfc_alloc_memdev(struct device *dev,
 	device_initialize(child);
 	dev_set_name(child, "%s:%s", dev_name(dev), name);
 	child->parent = dev;
-	child->bus = dev->bus;
 	child->coherent_dma_mask = dev->coherent_dma_mask;
 	child->dma_mask = dev->dma_mask;
 	child->release = s5p_mfc_memdev_release;