[PATCH 01/10] vfio: Move vfio_device driver open/close code to a function

[Tian, Kevin]

> From: Jason Gunthorpe <jgg at nvidia.com>
> Sent: Wednesday, October 26, 2022 2:17 AM
> 
> This error unwind is getting complicated. Move all the code into two
> pair'd function. The functions should be called when the open_count == 1
> after incrementing/before decrementing.
> 
> Signed-off-by: Jason Gunthorpe <jgg at nvidia.com>

Reviewed-by: Kevin Tian <kevin.tian at intel.com>, with a nit

> +	/*
> +	 * Here we pass the KVM pointer with the group under the read lock.

Now the read lock is replaced by mutex. Let's correct it when moving this
piece of code.