refind: Fix possible NULL dereference
refind: Fix possible NULL dereference

This was observed with U-Boot.

See the upstream change.

 - https://sourceforge.net/p/refind/code/merge-requests/45/

NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs,NixOS/nixpkgs