logging: Only compare the subscr address

Move the "logging filter imsi IMSI" into the BTS/NITB code to
allow to set the gsm_subscriber and only compare it. This way
we simply compare the subscriber address and don't have to care
if the subscriber data is still valid.
diff --git a/openbsc/src/libbsc/bsc_vty.c b/openbsc/src/libbsc/bsc_vty.c
index 3e7ac58..2857494 100644
--- a/openbsc/src/libbsc/bsc_vty.c
+++ b/openbsc/src/libbsc/bsc_vty.c
@@ -3183,22 +3183,6 @@
 		osmo_counter_get(net->stats.bts.rsl_fail), VTY_NEWLINE);
 }
 
-DEFUN(logging_fltr_imsi,
-      logging_fltr_imsi_cmd,
-      "logging filter imsi IMSI",
-	LOGGING_STR FILTER_STR
-      "Filter log messages by IMSI\n" "IMSI to be used as filter\n")
-{
-	struct log_target *tgt = osmo_log_vty2tgt(vty);
-
-	if (!tgt)
-		return CMD_WARNING;
-
-	log_set_imsi_filter(tgt, argv[0]);
-	return CMD_SUCCESS;
-}
-
-
 DEFUN(drop_bts,
       drop_bts_cmd,
       "drop bts connection <0-65535> (oml|rsl)",
@@ -3383,13 +3367,11 @@
 	install_element_ve(&show_ts_cmd);
 	install_element_ve(&show_lchan_cmd);
 	install_element_ve(&show_lchan_summary_cmd);
-	install_element_ve(&logging_fltr_imsi_cmd);
 
 	install_element_ve(&show_paging_cmd);
 	install_element_ve(&show_paging_group_cmd);
 
 	logging_vty_add_cmds(cat);
-	install_element(CFG_LOG_NODE, &logging_fltr_imsi_cmd);
 
 	install_element(CONFIG_NODE, &cfg_net_cmd);
 	install_node(&net_node, config_write_net);
diff --git a/openbsc/src/libbsc/paging.c b/openbsc/src/libbsc/paging.c
index 18bb3fe..2d08af7 100644
--- a/openbsc/src/libbsc/paging.c
+++ b/openbsc/src/libbsc/paging.c
@@ -250,12 +250,11 @@
 static void paging_T3113_expired(void *data)
 {
 	struct gsm_paging_request *req = (struct gsm_paging_request *)data;
-	struct gsm_subscriber *subscr = subscr_get(req->subscr);
 	void *cbfn_param;
 	gsm_cbfn *cbfn;
 	int msg;
 
-	log_set_context(BSC_CTX_SUBSCR, subscr);
+	log_set_context(BSC_CTX_SUBSCR, req->subscr);
 
 	LOGP(DPAG, LOGL_INFO, "T3113 expired for request %p (%s)\n",
 		req, req->subscr->imsi);
@@ -275,8 +274,6 @@
 		cbfn(GSM_HOOK_RR_PAGING, msg, NULL, NULL,
 			  cbfn_param);
 
-	log_set_context(BSC_CTX_SUBSCR, NULL);
-	subscr_put(subscr);
 }
 
 static int _paging_request(struct gsm_bts *bts, struct gsm_subscriber *subscr,