fix "libc}/lib" and similar references

Done mostly without any verification.
I didn't bother with libc}/include, as the path is still correct.

pkgs/os-specific/linux/klibc/shrunk.nix

@@ -8,10 +8,10 @@ stdenv.mkDerivation {
   name = "${klibc.name}";
   buildCommand = ''
     mkdir -p $out/lib
-    cp -prd ${klibc}/lib/klibc/bin $out/
-    cp -p ${klibc}/lib/*.so $out/lib/
+    cp -prd ${klibc.out}/lib/klibc/bin $out/
+    cp -p ${klibc.out}/lib/*.so $out/lib/
     chmod +w $out/*
-    old=$(echo ${klibc}/lib/klibc-*.so)
+    old=$(echo ${klibc.out}/lib/klibc-*.so)
     new=$(echo $out/lib/klibc-*.so)
     for i in $out/bin/*; do
       echo $i