cpufreq: differentiate between ondemand and conservative

In cpufreq widget, governor char is the same for ondemand and
conservative which makes it impossible to overload symbols to
different values for these two governors in a format function.

Signed-off-by: Adrian C. (anrxc) <anrxc@sysphere.org>

widgets/cpufreq.lua

@@ -25,7 +25,7 @@ local function worker(format, warg)
        ["powersave\n"]    = "⌁",
        ["userspace\n"]    = "¤",
        ["performance\n"]  = "⚡",
-       ["conservative\n"] = "↯"
+       ["conservative\n"] = "⊚"
     }
     -- Default voltage values
     local voltage = { v  = "N/A", mv = "N/A" }