tbf_free: Get rid of uneeded tbf_state transition

We are freeing the object immediately afterwards anyway, so no need to
pretend it went through the normal state release.
Leaving current state as it is actually provides more information on
what was the status/state at the time the TBF had to be freed.

Change-Id: I3016caaccc2c43e1e300f3c6042d69f8adcd9d69
diff --git a/tests/app_info/AppInfoTest.err b/tests/app_info/AppInfoTest.err
index 36234cb..c1c89c2 100644
--- a/tests/app_info/AppInfoTest.err
+++ b/tests/app_info/AppInfoTest.err
@@ -52,14 +52,14 @@
 Sending Packet Application Information to 2 subscribers with active TBF
 
 --- cleanup ---
-PDCH(bts=0,trx=0,ts=4) Detaching TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS), 1 TBFs, USFs = 00, TFIs = 00000002.
-PDCH(bts=0,trx=0,ts=5) Detaching TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS), 1 TBFs, USFs = 00, TFIs = 00000002.
-PDCH(bts=0,trx=0,ts=6) Detaching TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS), 1 TBFs, USFs = 00, TFIs = 00000002.
-PDCH(bts=0,trx=0,ts=7) Detaching TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS), 0 TBFs, USFs = 00, TFIs = 00000000.
-MS(TLLI=0xffffffff, IMSI=, TA=220, 10/11,) Detaching TBF: TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS)
-PDCH(bts=0,trx=0,ts=4) Detaching TBF(TFI=1 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS), 0 TBFs, USFs = 00, TFIs = 00000000.
-PDCH(bts=0,trx=0,ts=5) Detaching TBF(TFI=1 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS), 0 TBFs, USFs = 00, TFIs = 00000000.
-PDCH(bts=0,trx=0,ts=6) Detaching TBF(TFI=1 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS), 0 TBFs, USFs = 00, TFIs = 00000000.
-MS(TLLI=0xffffffff, IMSI=, TA=220, 12/13,) Detaching TBF: TBF(TFI=1 TLLI=0xffffffff DIR=DL STATE=RELEASING EGPRS)
+PDCH(bts=0,trx=0,ts=4) Detaching TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS), 1 TBFs, USFs = 00, TFIs = 00000002.
+PDCH(bts=0,trx=0,ts=5) Detaching TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS), 1 TBFs, USFs = 00, TFIs = 00000002.
+PDCH(bts=0,trx=0,ts=6) Detaching TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS), 1 TBFs, USFs = 00, TFIs = 00000002.
+PDCH(bts=0,trx=0,ts=7) Detaching TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS), 0 TBFs, USFs = 00, TFIs = 00000000.
+MS(TLLI=0xffffffff, IMSI=, TA=220, 10/11,) Detaching TBF: TBF(TFI=0 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS)
+PDCH(bts=0,trx=0,ts=4) Detaching TBF(TFI=1 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS), 0 TBFs, USFs = 00, TFIs = 00000000.
+PDCH(bts=0,trx=0,ts=5) Detaching TBF(TFI=1 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS), 0 TBFs, USFs = 00, TFIs = 00000000.
+PDCH(bts=0,trx=0,ts=6) Detaching TBF(TFI=1 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS), 0 TBFs, USFs = 00, TFIs = 00000000.
+MS(TLLI=0xffffffff, IMSI=, TA=220, 12/13,) Detaching TBF: TBF(TFI=1 TLLI=0xffffffff DIR=DL STATE=NULL EGPRS)
 MS(TLLI=0xffffffff, IMSI=, TA=220, 12/13,) Destroying MS object
 MS(TLLI=0xffffffff, IMSI=, TA=220, 10/11,) Destroying MS object