gsm_12_21.h: Fix abis_nm_avail_state InTest and Failed values

This has always been wrong since at least libosmocore initial commit in
2010.

Change-Id: Ib854a1284fbd38951bb2d1cb3706c42ba7e14ccb
diff --git a/include/osmocom/gsm/protocol/gsm_12_21.h b/include/osmocom/gsm/protocol/gsm_12_21.h
index 9fe6a8b..4baa7e8 100644
--- a/include/osmocom/gsm/protocol/gsm_12_21.h
+++ b/include/osmocom/gsm/protocol/gsm_12_21.h
@@ -522,9 +522,11 @@
 
 /*! OML Availability State (Section 9.4.7) */
 enum abis_nm_avail_state {
-	NM_AVSTATE_IN_TEST	= 1,
+	NM_AVSTATE_IN_TEST	= 0,
+	NM_AVSTATE_FAILED	= 1,
 	NM_AVSTATE_POWER_OFF	= 2,
 	NM_AVSTATE_OFF_LINE	= 3,
+	/* <not used> = 4, */
 	NM_AVSTATE_DEPENDENCY	= 5,
 	NM_AVSTATE_DEGRADED	= 6,
 	NM_AVSTATE_NOT_INSTALLED= 7,