install-darwin: track mount permission edge-case fix
install-darwin: track mount permission edge-case fix

Same as 1fd127a06833c19a5a2965bd41cf4f695773cca6, but applied to a
code path (volume_pass_works -> verify_volume_pass) that the reporting
user didn't hit and wasn't able to trigger manually. I am not certain
but I suspect it will be easier to add prophylactically than to debug
if its absence causes trouble some day.

NixOS/nix,NixOS/nix,NixOS/nix,rycee/nix,rycee/nix,rycee/nix,NixOS/nix,NixOS/nix,rycee/nix,rycee/nix