Revert "tbf: Add state WAIT_ASSIGN"

This reverts commit f1a7b8fc6651f92a8b7f3f27b7ca05d07f4e44e0.

Conflicts:
	tests/tbf/TbfTest.err

The commit broke GPRS service at least for osmo-bts-sysmo on a SysmoBTS 1002
with current master of osmo-bts (ef30f50d5d6d5f863fc147d05ccdceb89284934e).

The error observed is the following log output (was viewing both osmo-bts-sysmo
and osmo-pcu logs interleaved):

<0002> tbf.cpp:874 TBF(TFI=0 TLLI=0x00000000 DIR=UL STATE=WAIT ASSIGN) T3169 timeout during transsmission
<0002> tbf.cpp:893 - Assignment was on CCCH
<0002> tbf.cpp:899 - No uplink data received yet
<0007> l1sap.c:904 RACH for packet access
<0001> pcu_l1_if.cpp:311 RACH request received: sapi=1 qta=0, ra=121, fn=13653
[repeat]

When removing this single commit from current osmo-pcu master, GPRS service
works well on SysmoBTS, with current osmo-bts master.

The TbfTest.err expected output needed adjustment after the revert.

Disclaimer: I am not aware of adverse effects this commit may have. I have no
idea what the WAIT_ASSIGN state is used for -- further review is required.

Change-Id: I1532f8e93194368cdc1e3846f82afa6d68cd5fbd
5 files changed