linux_mptcp: makes linux_mptcp.override works

I needed to override some parameters because of an error I had:
"Error: modDirVersion specified in the Nix expression is wrong, it should be: 4.9.60+"

but the following override would not be taken into account
  pkg.override ({
    modDirVersion="4.9.60+";
    src=pkgs.lib.cleanSource /home/teto/mptcp;
  })

because the override would be overriden by the nixpkgs parameters
because of concatenation order:
https://nixos.org/nix/manual/#sec-language-operators

1 files changed, 2 insertions, 2 deletions

diff --git a/pkgs/os-specific/linux/kernel/linux-mptcp.nix b/pkgs/os-specific/linux/kernel/linux-mptcp.nix
index c7e9859ded79..92b202100a63 100644
--- a/pkgs/os-specific/linux/kernel/linux-mptcp.nix
+++ b/pkgs/os-specific/linux/kernel/linux-mptcp.nix
@@ -1,6 +1,6 @@
 { stdenv, hostPlatform, fetchFromGitHub, perl, buildLinux, ... } @ args:
 
-import ./generic.nix (args // rec {
+import ./generic.nix (rec {
   mptcpVersion = "0.93";
   modDirVersion = "4.9.60";
   version = "${modDirVersion}-mptcp_v${mptcpVersion}";
@@ -43,4 +43,4 @@ import ./generic.nix (args // rec {
     TCP_CONG_BALIA m
 
   '' + (args.extraConfig or "");
-} // (args.argsOverride or {}))
+} // args // (args.argsOverride or {}))