ocs: Fix a couple of type mismatches in function prototypes

Reported by: GCC 13 via -Wenum-int-mismatch
Reviewed by: imp, emaste
Differential Revision: https://reviews.freebsd.org/D42585

(cherry picked from commit 7aa5b2a9e7f5f3cd33e72cb1e95790fe7637f10f)