vty: Use vty_install_default() instead of bsc_install_default()

Remove ournode_exit_cmd, ournode_end_cmd, and bsc_install_default()
since this functionality is provided by the current libosmocore.

Replace calls to bsc_install_default() by call to
vty_install_default() with the following semantic patch:

    @rule1@
    expression N;
    @@
    - bsc_install_default(N);
    + vty_install_default(N);

Ticket: OW#952
Sponsored-by: On-Waves ehf
diff --git a/openbsc/src/libbsc/bsc_vty.c b/openbsc/src/libbsc/bsc_vty.c
index 5d03b2a..5a9976b 100644
--- a/openbsc/src/libbsc/bsc_vty.c
+++ b/openbsc/src/libbsc/bsc_vty.c
@@ -3101,7 +3101,7 @@
 
 	install_element(CONFIG_NODE, &cfg_net_cmd);
 	install_node(&net_node, config_write_net);
-	bsc_install_default(GSMNET_NODE);
+	vty_install_default(GSMNET_NODE);
 	install_element(GSMNET_NODE, &cfg_net_ncc_cmd);
 	install_element(GSMNET_NODE, &cfg_net_mnc_cmd);
 	install_element(GSMNET_NODE, &cfg_net_name_short_cmd);
@@ -3137,7 +3137,7 @@
 
 	install_element(GSMNET_NODE, &cfg_bts_cmd);
 	install_node(&bts_node, config_write_bts);
-	bsc_install_default(BTS_NODE);
+	vty_install_default(BTS_NODE);
 	install_element(BTS_NODE, &cfg_bts_type_cmd);
 	install_element(BTS_NODE, &cfg_description_cmd);
 	install_element(BTS_NODE, &cfg_no_description_cmd);
@@ -3199,7 +3199,7 @@
 
 	install_element(BTS_NODE, &cfg_trx_cmd);
 	install_node(&trx_node, dummy_config_write);
-	bsc_install_default(TRX_NODE);
+	vty_install_default(TRX_NODE);
 	install_element(TRX_NODE, &cfg_trx_arfcn_cmd);
 	install_element(TRX_NODE, &cfg_description_cmd);
 	install_element(TRX_NODE, &cfg_no_description_cmd);
@@ -3211,7 +3211,7 @@
 
 	install_element(TRX_NODE, &cfg_ts_cmd);
 	install_node(&ts_node, dummy_config_write);
-	bsc_install_default(TS_NODE);
+	vty_install_default(TS_NODE);
 	install_element(TS_NODE, &cfg_ts_pchan_cmd);
 	install_element(TS_NODE, &cfg_ts_pchan_compat_cmd);
 	install_element(TS_NODE, &cfg_ts_tsc_cmd);