linuxPackages.amdgpu-pro: use libffi_3_3, not an override

Without the change `amdgpu-pro` tried to build `libffi-3.3` with patches
for `libffi-3.4` and failed as:

    patching file include/ffi_common.h
    Hunk #1 succeeded at 103 with fuzz 2 (offset -25 lines).
    can't find file to patch at input line 36

THe change uses `libffi_3_3` instead.

Closes: NixOS#279955

pkgs/os-specific/linux/amdgpu-pro/default.nix

@@ -9,7 +9,7 @@
 , perl
 , zlib
 , expat
-, libffi
+, libffi_3_3
 , libselinux
 , libdrm
 , udev
@@ -119,7 +119,7 @@ in stdenv.mkDerivation rec {
     libxshmfence
     elfutils
     expat
-    libffi
+    libffi_3_3
     libselinux
     # libudev is not listed in any dependencies, but is loaded dynamically
     udev

pkgs/top-level/linux-kernels.nix

@@ -298,15 +298,7 @@ in {
 
     akvcam = callPackage ../os-specific/linux/akvcam { };
 
-    amdgpu-pro = callPackage ../os-specific/linux/amdgpu-pro {
-      libffi = pkgs.libffi.overrideAttrs (orig: rec {
-        version = "3.3";
-        src = fetchurl {
-          url = "https://github.com/libffi/libffi/releases/download/v${version}/${orig.pname}-${version}.tar.gz";
-          sha256 = "0mi0cpf8aa40ljjmzxb7im6dbj45bb0kllcd09xgmp834y9agyvj";
-        };
-      });
-    };
+    amdgpu-pro = callPackage ../os-specific/linux/amdgpu-pro { };
 
     apfs = callPackage ../os-specific/linux/apfs { };