common/pcu_sock.c: fix possible memleaks in pcu_sock_read()
common/pcu_sock.c: fix possible memleaks in pcu_sock_read()

Change-Id: I58352e5f2b5715361c7089d0e134a42975171022

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