E3-1417: Two bugfixes

First bugfix

If you have a waveform-type array (aai, waveform, etc.) and have caputlog loaded and initialised, then the IOC will no longer send out pvmonitors on changes (though it still sends on CA monitors). This seems to be due to a bug in PVAccessCPP about caching of PV channels; when we hit the caPutLog callback code on a put, we modify the original pchan in memory causing a comparison in the db event code (db_post_events) to fail.

This patch is a minimal fix to caPutLog to get rid of the problem. While the actual issue seems to be a PVAccessCPP one, it seems that the latest version of PVXS does not have this problem. As such it seems simpler to fix it here instead of digging deeply into code that ultimately will be no longer in use in a few years.

Second bugfix

A ca/pvput to an array only would log the first entry.