virtio-mmio: Use to_virtio_mmio_device() to simply code

stable inclusion
from stable-v5.10.192
commit b1fe05cc51262fb071908faee549bfd923fca808
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I933RF

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=b1fe05cc51262fb071908faee549bfd923fca808



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[ Upstream commit da98b54d ]

The file virtio_mmio.c has defined the function to_virtio_mmio_device,
so use it instead of container_of() to simply code.

Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Link: https://lore.kernel.org/r/20210222055724.220-1-tangbin@cmss.chinamobile.com


Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Stable-dep-of: 55c91fed ("virtio-mmio: don't break lifecycle of vm_dev")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: sanglipeng <sanglipeng1@jd.com>