misc: Fix compilation warnings

bsc_api.c:417:3: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 7 has type ‘unsigned int’ [-Wformat]
bsc_api.c: In function ‘handle_ass_fail’:
bsc_api.c:458:3: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 7 has type ‘unsigned int’ [-Wformat]

db.c: In function ‘db_sync_subscriber’:
db.c:785:3: warning: format ‘%i’ expects argument of type ‘int’, but argument 8 has type ‘time_t’ [-Wformat]

osmo_msc.c: In function ‘msc_release_connection’:
osmo_msc.c:145:20: warning: unused variable ‘trans’ [-Wunused-variable]

smpp_smsc.c: In function ‘link_accept_cb’:
smpp_smsc.c:891:24: warning: assignment from incompatible pointer type [enabled by default]

smpp_smsc.c:271:1: warning: ‘esme_by_system_id’ defined but not used [-Wunused-function]

smpp_openbsc.c: In function ‘smpp_openbsc_init’:
smpp_openbsc.c:545:2: warning: implicit declaration of function ‘smpp_vty_init’ [-Wimplicit-function-declaration]

osmo_bsc_ctrl.c: In function ‘verify_bts_loc’:
osmo_bsc_ctrl.c:340:19: warning: variable ‘height’ set but not used [-Wunused-but-set-variable

smpp_mirror.c: In function ‘main’:
smpp_mirror.c:297:2: warning: implicit declaration of function ‘osmo_init_logging’ [-Wimplicit-function-declaration]
diff --git a/openbsc/src/osmo-bsc/osmo_bsc_ctrl.c b/openbsc/src/osmo-bsc/osmo_bsc_ctrl.c
index c82ffc9..72abcf4 100644
--- a/openbsc/src/osmo-bsc/osmo_bsc_ctrl.c
+++ b/openbsc/src/osmo-bsc/osmo_bsc_ctrl.c
@@ -337,7 +337,7 @@
 	char *saveptr, *latstr, *lonstr, *heightstr, *tstampstr, *validstr, *tmp;
 	time_t tstamp;
 	int valid;
-	double lat, lon, height;
+	double lat, lon, height __attribute__((unused));
 
 	tmp = talloc_strdup(cmd, value);
 	if (!tmp)