tbf: Don't log rlcmac_diag() output in separate lines

Output of all diag in different lines is really confusing, since the
user reads a timeout ocurred and then later in another line something
like "Downlink ACK was received" while no GSMTAP message shows any ACK.

Change-Id: I6a7d79c16c930f0712bc73b308409ececb1946ba
diff --git a/tests/tbf/TbfTest.err b/tests/tbf/TbfTest.err
index 681e7a3..ce23802 100644
--- a/tests/tbf/TbfTest.err
+++ b/tests/tbf/TbfTest.err
@@ -1725,9 +1725,7 @@
 Searching for first unallocated TFI: TRX=0
  Found TFI=1.
 TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=FINISHED) poll timeout for FN=2654292, TS=7 (curr FN 2654335)
-TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=FINISHED) Timeout for polling PACKET DOWNLINK ACK.
-TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=FINISHED) Assignment was on PACCH
-TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=FINISHED) No downlink ACK received yet
+TBF(TFI=0 TLLI=0xf1223344 DIR=DL STATE=FINISHED) Timeout for polling PACKET DOWNLINK ACK: |Assignment was on PACCH|No downlink ACK received yet|
 +++++++++++++++++++++++++ RX : Uplink Control Block +++++++++++++++++++++++++
 ------------------------- RX : Uplink Control Block -------------------------
 Creating MS object, TLLI = 0x00000000