sif: pqp: Fix potential null pointer exception under high load

sif: pqp: Fix potential null pointer exception under high load

If a high number of invalidate requests are posted
without requesting completions, the PQP may run full
enough not to be able to allow a posted req anymore.

To handle this scenario, an additional attempt to send a
synchronous invalidate request was added. Unfortunately
that request ended up being posted with synchronous semantics
but without a handle to handle the completion.

This commit fixes this case by dynamically allocating/freeing
a handle in such situations.

Orabug: 24316139

Signed-off-by: Knut Omang <knut.omang@oracle.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>