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: Ib2ec5e4884aa90f48051ee2f832af557aa525991
diff --git a/openbsc/src/libmsc/smpp_openbsc.c b/openbsc/src/libmsc/smpp_openbsc.c
index fdafa16..2703a24 100644
--- a/openbsc/src/libmsc/smpp_openbsc.c
+++ b/openbsc/src/libmsc/smpp_openbsc.c
@@ -67,7 +67,7 @@
 	}
 
 	/* tag the context in case we know it */
-	log_set_context(LOGGING_CTX_VLR_SUBSCR, subscr);
+	log_set_context(LOG_CTX_VLR_SUBSCR, subscr);
 	return subscr;
 }