bts-trx: sched: tx_pdtch_fn: Drop log line clogging logs
bts-trx: sched: tx_pdtch_fn: Drop log line clogging logs

The burst is properly pre-filled to _sched_dummy_burst in
bts_sched_init_buffers(), so we are fine doing nothing on C0.

Related: SYS#5676
Related: SYS#4919
Fixes: 300e31ed135c674cd44526b7503d4664a45a9ec3

Change-Id: Ia7045724a1a3206f5890c0b12843711ad2360ed8

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