Fix evaluation errors in libndtypes and libxnd.

pkgs/top-level/all-packages.nix

···
 
   lief = callPackage ../development/libraries/lief {};
 
-  libndtypes = callPackages ../development/libraries/libndtypes { };
+  libndtypes = callPackage ../development/libraries/libndtypes { };
 
-  libxnd = callPackages ../development/libraries/libxnd { };
+  libxnd = callPackage ../development/libraries/libxnd { };
 
   loadwatch = callPackage ../tools/system/loadwatch { };