osmo-bts-trx: Remove duplicate parsing of NM_ATT_CONN_FAIL_CRIT
osmo-bts-trx: Remove duplicate parsing of NM_ATT_CONN_FAIL_CRIT

For some reason, osmo-bts-trx did another take at parsing
NM_ATT_CONN_FAIL_CRIT and storing the second octet in
btsb->radio_link_timeout, just like the generic code already does in
oml_rx_set_bts_attr(), but without proper checking and any error
message.  Let's remove it.

Change-Id: Idb0179e1443c0b5a97e59919dba684a001e90192

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