PROBLEM:
1) ha_ndbcluster::unpack_record() uses DBUG_ASSERT() in many places to check
the return values from different function. But this check will not fail in the
release libraries.
2) "res" local variables left unused and gives compiler warning.

FIX:
Used ndbcluster::ndbrequire() in place of DEBUG_ASSERT(), which fails in both release and debug
libraries. Cleared compiler warnings.