Same as dm_logger_append, except it takes a va_list instead of a
variable number of arguments. dm_logger_append is now a minimal wrapper
around dm_logger_append_va.
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NMichel Dänzer <michel.daenzer@amd.com>
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>