logging: use central filter and ctx consts from libosmocore

The LCHAN and BTS filter contexts are actually never used, so drop them until
someone adds them properly.

For now use only LOGGING_{FILTER,CTX}_VLR_SUBSCR. Some of these will change to
_BSC_SUBSCR once struct bsc_subscriber is introduced, and later on, struct
gsm_subscriber will be replaced by vlr_subscriber so that the names will match.

Depends: libosmocore change-id I5c343630020f4b108099696fd96c2111614c8067
Change-Id: Ifa82f6a461ad4c0eeddb8a38fb3833460432d16b
diff --git a/openbsc/src/libbsc/abis_rsl.c b/openbsc/src/libbsc/abis_rsl.c
index 541a86d..58fdaa3 100644
--- a/openbsc/src/libbsc/abis_rsl.c
+++ b/openbsc/src/libbsc/abis_rsl.c
@@ -158,9 +158,8 @@
 		LOGP(DRSL, LOGL_ERROR, "%s %smismatching chan_nr=0x%02x\n",
 		     gsm_ts_and_pchan_name(lchan->ts), log_name, chan_nr);
 
-	log_set_context(BSC_CTX_LCHAN, lchan);
 	if (lchan->conn)
-		log_set_context(BSC_CTX_SUBSCR, lchan->conn->subscr);
+		log_set_context(LOGGING_CTX_VLR_SUBSCR, lchan->conn->subscr);
 
 	return lchan;
 }