fix all valgrind warnings in t/ndb_dd (except replication related)


sql/ha_ndbcluster.cc:
  Fix memleak
storage/ndb/include/kernel/signaldata/DictTabInfo.hpp:
  Fix valgrind warning
storage/ndb/include/kernel/signaldata/DropFilegroup.hpp:
  Fix valgrind warning
storage/ndb/src/common/debugger/signaldata/DictTabInfo.cpp:
  Fix valgrind warning
storage/ndb/src/kernel/blocks/dbdict/Dbdict.cpp:
  Fix valgrind warning
storage/ndb/src/kernel/blocks/dbdict/Dbdict.hpp:
  Fix valgrind warning
storage/ndb/src/ndbapi/NdbDictionaryImpl.cpp:
  Fix valgrind warning
storage/ndb/src/ndbapi/ndberror.c:
  Fix valgrind warning