bursts test: test_pdtch: pre-init result mem
bursts test: test_pdtch: pre-init result mem

Fixes: CID#57943
Change-Id: I4547f47c4150759d5c4ab790e34e91b784b03b39

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