ctrl: Remember last 'rf_locked' control command

This stores the last SET rf_locked control command along with a
timestamp. The 'show network' vty command is extended to show
this information.

Ticket: OW#659
diff --git a/openbsc/src/libbsc/bsc_vty.c b/openbsc/src/libbsc/bsc_vty.c
index 55564b6..3fb8516 100644
--- a/openbsc/src/libbsc/bsc_vty.c
+++ b/openbsc/src/libbsc/bsc_vty.c
@@ -210,6 +210,10 @@
 		vty_out(vty, "  Last RF Command: %s%s",
 			net->bsc_data->rf_ctrl->last_state_command,
 			VTY_NEWLINE);
+	if (net->bsc_data && net->bsc_data->rf_ctrl)
+		vty_out(vty, "  Last RF Lock Command: %s%s",
+			net->bsc_data->rf_ctrl->last_rf_lock_ctrl_command,
+			VTY_NEWLINE);
 }
 
 DEFUN(show_net, show_net_cmd, "show network",