Problem

In the implementation of the LF_HASH,
Out Of Memory conditions (OOM)
are triggering error code path that may leak memory.

This was found by code review.

Solution

Analyze the code for OOM error paths,
and add cleanup when necessary.

In particular:

In lf_alloc_new(),
do not call the LF_ALLOCATOR::constructor
when no node is allocated.

In lf_hash_insert(),
free the allocated "node" structure on various error paths,
as per the bug report.

In initialize_bucket(),
free the allocated "dummy" structure on various error paths.

With this fix, the LF_HASH implementation is more resilient
to OOM conditions.

Approved by: Chris Powers <chris.powers@oracle.com>