d37b642769
the kernel itself (and busybox's cifs mount code) are no longer able to do this in some/most cases and will error out saying: "CIFS VFS: connecting to DFS root not implemented yet"" Nixos' qemu-vm target is hurt by this, as it wants to mount /nix/store via cifs very early in the boot process. this commit just marks the problematic kernels. An associated commit in nixos will use this info to fix the problem.