nixos/btrfs: use sha256 instead of sha256_generic

Upstream dropped `sha256_generic` in https://github.com/torvalds/linux/commit/e96cb9507f2d8ba150d417dcd283204564945831

Quoting from upstream:

> sha256_blocks_generic() is moved from lib/crypto/sha256-generic.c into
lib/crypto/sha256.c. It's now a static function marked with
__maybe_unused, so the compiler automatically eliminates it in any
cases where it's not used.

Co-authored-by: dramforever <dramforever@live.com>

Changed files
+3 -1
nixos
modules
tasks
filesystems
+3 -1
nixos/modules/tasks/filesystems/btrfs.nix
···
# Needed for mounting filesystems with new checksums
"xxhash_generic"
"blake2b_generic"
-
"sha256_generic" # Should be baked into our kernel, just to be sure
+
+
# `sha256` is always available, whereas `sha256_generic` is not available from 6.17 onwards
+
"sha256" # Should be baked into our kernel, just to be sure
];
boot.initrd.extraUtilsCommands = mkIf (!config.boot.initrd.systemd.enable) ''