logging fixup: shorter names for LOGGING_FILTER_* and LOGGING_CTX_*

In libosmocore, my patch was merged to master a bit too soon. To accomodate the
request for naming that matches the general "LOG" prefix instead of "LOGGING",
a fixup was committed to libosmocore. Adjust for that.

Original patch: change-id I5c343630020f4b108099696fd96c2111614c8067
The fixup: change-id I424fe3f12ea620338902b2bb8230544bde3f1a93

Change-Id: I4db4a668f2be07f3d55f848d38d1b490d8a7a685
diff --git a/src/gprs_bssgp_pcu.cpp b/src/gprs_bssgp_pcu.cpp
index f07b3a6..c4ff402 100644
--- a/src/gprs_bssgp_pcu.cpp
+++ b/src/gprs_bssgp_pcu.cpp
@@ -365,7 +365,7 @@
 
 	if (bctx)
 	{
-		log_set_context(LOGGING_CTX_GB_BVC, bctx);
+		log_set_context(LOG_CTX_GB_BVC, bctx);
 		rate_ctr_inc(&bctx->ctrg->ctr[BSSGP_CTR_PKTS_IN]);
 		rate_ctr_add(&bctx->ctrg->ctr[BSSGP_CTR_BYTES_IN], msgb_bssgp_len(msg));
 	}