another small fix in thermal_freebsd.lua

widgets/thermal_freebsd.lua

@@ -14,6 +14,7 @@ local thermal_freebsd = {}
 -- {{{ Thermal widget type
 local function worker(format, warg)
     if not warg then return end
+    if type(warg) ~= "table" then warg = { warg } end
 
     local thermals = {}