sd-varlink: add sd_varlink_get_description() call

src/libsystemd/libsystemd.sym

@@ -1067,6 +1067,7 @@ global:
         sd_json_variant_type_to_string;
         sd_json_variant_unset_field;
         sd_varlink_get_current_method;
+        sd_varlink_get_description;
         sd_varlink_get_input_fd;
         sd_varlink_get_output_fd;
         sd_varlink_reset_fds;

src/libsystemd/sd-varlink/sd-varlink.c

@@ -2916,6 +2916,12 @@ _public_ int sd_varlink_set_description(sd_varlink *v, const char *description)
         return free_and_strdup(&v->description, description);
 }
 
+_public_ const char* sd_varlink_get_description(sd_varlink *v) {
+        assert_return(v, NULL);
+
+        return v->description;
+}
+
 static int io_callback(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
         sd_varlink *v = ASSERT_PTR(userdata);