Revert "grsecurity: work around for #20490"

This reverts commit e38b74ba89.

I failed to notice f19c961b4e461da045f2e72e73701059e5117be0; better
use that fix instead.

pkgs/os-specific/linux/kernel/grsecurity-modinst.patch

@@ -1,12 +0,0 @@
-diff -ruN a/scripts/Makefile.modinst b/scripts/Makefile.modinst
---- a/scripts/Makefile.modinst	2016-11-15 07:49:06.000000000 +0100
-+++ b/scripts/Makefile.modinst	2016-11-18 13:45:07.977270500 +0100
-@@ -9,7 +9,7 @@
- 
- #
- 
--__modules := $(sort $(shell grep -h '\.ko$$' /dev/null $(wildcard $(MODVERDIR)/*.mod)))
-+__modules := $(shell find $(MODVERDIR) -name '*.mod' -exec grep -h '\.ko$$' '{}' \; | sort)
- modules := $(patsubst %.o,%.ko,$(wildcard $(__modules:.ko=.o)))
- 
- PHONY += $(modules)

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

@@ -99,14 +99,6 @@ rec {
       patch = ./grsecurity-nixos-kmod.patch;
     };
 
-  # A temporary work-around for execvp: arglist too long error during
-  # module_install.  Without this, no modules are installed into the
-  # resulting output.
-  grsecurity_modinst =
-    { name = "grsecurity-modinst";
-      patch = ./grsecurity-modinst.patch;
-    };
-
   crc_regression =
     { name = "crc-backport-regression";
       patch = ./crc-regression.patch;

pkgs/top-level/all-packages.nix

@@ -11207,7 +11207,7 @@ in
         ];
     };
     grsecPatch = self.kernelPatches.grsecurity_testing;
-    kernelPatches = with self.kernelPatches; [ grsecurity_nixos_kmod grsecurity_modinst ];
+    kernelPatches = [ self.kernelPatches.grsecurity_nixos_kmod ];
     extraConfig = callPackage ../os-specific/linux/kernel/grsecurity-nixos-config.nix { };
   };