FENNEL:  fix close without prepare in LhxJoinExecStream (LER-1721)
FENNEL:  fix close without prepare in LhxJoinExecStream (LER-1721)

[git-p4: depot-paths = "//open/lu/dev/": change = 7315]

LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb,LucidDB/luciddb