Simplify TS alloc: use defines for constants

* define and use constant for occupied TFI instead copying the same
  magic number all over the place
* use libosmocore's define for bit pretty-printer

Change-Id: I2699ceebf0cbec01652a02fa68ccc9e9419d0293
Related: OS#2282
diff --git a/tests/alloc/AllocTest.cpp b/tests/alloc/AllocTest.cpp
index 6e344dc..1c98e46 100644
--- a/tests/alloc/AllocTest.cpp
+++ b/tests/alloc/AllocTest.cpp
@@ -585,17 +585,17 @@
 				continue;
 
 			if (ul_tbf &&
-				pdch->assigned_tfi(GPRS_RLCMAC_DL_TBF) != 0xffffffff)
+				pdch->assigned_tfi(GPRS_RLCMAC_DL_TBF) != NO_FREE_TFI)
 				continue;
 
 			if (dl_tbf &&
-				pdch->assigned_tfi(GPRS_RLCMAC_UL_TBF) != 0xffffffff)
+				pdch->assigned_tfi(GPRS_RLCMAC_UL_TBF) != NO_FREE_TFI)
 				continue;
 
 			busy_slots |= 1 << i;
 		}
 
-		printf(" TBF[%d] class %d reserves %c%c%c%c%c%c%c%c\n",
+		printf(" TBF[%d] class %d reserves " OSMO_BIT_SPEC "\n",
 			tfi, ms_class,
 			get_dir_char(0x01, ul_slots, dl_slots, busy_slots),
 			get_dir_char(0x02, ul_slots, dl_slots, busy_slots),