SBUS: Silence warning maybe-uninitialized
    
    It should not happen because function sbus_interface_find_property
    should return NULL for access different than SBUS_PROPERTY_READABLE
    or SBUS_PROPERTY_WRITABLE. And thus we would return ERR_SBUS_UNKNOWN_PROPERTY
    from the function sbus_request_property.
    
    src/sbus/interface/sbus_properties.c: In function 'sbus_request_property.isra.0':
    src/sbus/interface/sbus_properties.c:360:14:
      error: 'type' may be used uninitialized in this function
      [-Werror=maybe-uninitialized]
         sbus_req = sbus_request_create(mem_ctx, conn, type, destination,
         ~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                        interface_name, property_name, path);
                                        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    cc1: all warnings being treated as errors
    
    Merges: https://pagure.io/SSSD/sssd/pull-request/3851
    
    Reviewed-by: Pavel Březina <pbrezina@redhat.com>