mdbx-test: backport - fix osal_actor_poll() for 32-bit builds.
mdbx-test: backport - fix osal_actor_poll() for 32-bit builds.

Change-Id: I36b2f955295d8ca5435a68737c0c2e7f069bfe34

leo-yuriev/libfpta,leo-yuriev/libfpta