tests/partition: Check if nixpart loses mounts.
tests/partition: Check if nixpart loses mounts.

As the whole partitioning run is quite an invasive procedure, we want to
especially make sure that it doesn't unmount any filesystems that were mounted
before the partitioner was run.

Signed-off-by: aszlig <ee1aa092358634f9c53f01b5a783726c9e21b35a@redmoonstudios.org>

triton/triton,NixOS/nixpkgs,triton/triton,triton/triton,NixOS/nixos,NixOS/nixpkgs,NixOS/nixos,NixOS/nixpkgs,NixOS/nixpkgs,andreassalomonsson/nixos,andreassalomonsson/nixos,andreassalomonsson/nixos,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,triton/triton,andreassalomonsson/nixos,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,andreassalomonsson/nixos,triton/triton,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,triton/triton,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,triton/triton,NixOS/nixpkgs,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixos,NixOS/nixos,NixOS/nixos,triton/triton,NixOS/nixos,SymbiFlow/nixpkgs,SymbiFlow/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,andreassalomonsson/nixos