In ol_txrx_peer_release_ref, it is possible that this function is
scheduled out when just unlock peer_ref_mutex, unmap event will
come to decrease ref_cnt and free peer object, when
ol_txrx_peer_release_ref is scheduled back and access peer info,
it will cause use-after-free.
Get peer info in the protection of peer_ref_mutex.
Change-Id: Ic442f53e0993a931c4411d9dbc85f04d6a85dc46
CRs-Fixed: 2180584