socklog: disable shsgr test

Running the chkhsgr test on Hydra fails with
```
./chkshsgr || ( cat warn-shsgr; exit 1 )
Oops. Your getgroups() returned 0, and setgroups() failed; this means
that I can't reliably do my shsgr test. Please either ``make'' as root
or ``make'' while you're in one or more supplementary groups.
```

We just assume that our supported platforms have working
getgroups()/setgroups().

pkgs/tools/system/socklog/default.nix

@@ -15,6 +15,10 @@ stdenv.mkDerivation rec {
 
   outputs = [ "out" "man" "doc" ];
 
+  postPatch = ''
+    sed -i src/TARGETS -e '/^chkshsgr/d'
+  '';
+
   configurePhase = ''
     echo "$NIX_CC/bin/cc $NIX_CFLAGS_COMPILE"   >src/conf-cc
     echo "$NIX_CC/bin/cc -s"                    >src/conf-ld