oc2g: Fix returning values on void function
oc2g: Fix returning values on void function

Similar to what's done in I7a944c0636933c0389db9aabd8b5e6c173052f12 for
lc15.

Change-Id: I6f5e976969af994011bc9282ede115606f0f0d20

osmocom/osmo-bts,osmocom/osmo-bts,osmocom/osmo-bts