Check only allocated mv bufs for releasing from reference

When checking mv bufs for releasing from reference, unallocated
mv bufs were also checked. This issue was fixed by restricting
the loop count to allocated number of mv bufs.

Bug: 34896906
Bug: 34819017

Change-Id: If832f590b301f414d4cd5206414efc61a70c17cb
(cherry picked from commit 23bfe3e06d53ea749073a5d7ceda84239742b2c2)
