fix typo + add error code to printable list


storage/ndb/include/kernel/signaldata/Extent.hpp:
  Set correct error code
storage/ndb/src/kernel/blocks/dbtup/DbtupDiskAlloc.cpp:
  err is already negative
storage/ndb/src/kernel/blocks/dbtup/DbtupExecQuery.cpp:
  Set correct error code
storage/ndb/src/ndbapi/ndberror.c:
  Add error code to printable list