hashdeep: simplify platforms

pkgs/tools/security/hashdeep/default.nix

···
     description = "A set of cross-platform tools to compute hashes";
     homepage = "https://github.com/jessek/hashdeep";
     license = licenses.gpl2;
+    maintainers = [ maintainers.karantan ];
+    platforms = platforms.all;
     # Build fails on Darwin:
     # > ./xml.h:103:82: error: invalid suffix on literal; C++11 requires a space between literal and identifier [-Wreserved-user-defined-literal]
     # >     void xmlout(const std::string &tag,const int64_t value){ xmlprintf(tag,"","%"PRId64,value); }
-    platforms = with platforms; linux ++ freebsd ++ openbsd;
-    maintainers = [ maintainers.karantan ];
+    broken = stdenv.isDarwin;
   };
 }