linux: use consistent rustc and rust-bindgen

If we're going to use the unwrapped versions, we should do so
consistently in both parts of the kernel build, not mix and match.

Fixes: e9b2edb491 ("linux: un-simplify toolchain selection")

pkgs/os-specific/linux/kernel/generic.nix

@@ -190,7 +190,7 @@ let
         ]
         ++ lib.optional (lib.versionAtLeast version "5.2") pahole
         ++ lib.optionals withRust [
-          rust-bindgen
+          rust-bindgen.unwrapped
           rustc.unwrapped
         ];
 

pkgs/os-specific/linux/kernel/manual-config.nix

@@ -169,7 +169,7 @@ lib.makeOverridable (
         ]
         ++ optional (lib.versionAtLeast version "5.13") zstd
         ++ optionals withRust [
-          rustc
+          rustc.unwrapped
           rust-bindgen.unwrapped
         ];
 
@@ -229,7 +229,7 @@ lib.makeOverridable (
           zlib
         ]
         ++ optionals withRust [
-          rustc
+          rustc.unwrapped
           rust-bindgen.unwrapped
         ];