Revert bat_openbsd since the change is unnecessary

widgets/bat_openbsd.lua

@@ -34,17 +34,18 @@ local STATES = { [0] = "↯",         -- not charging
 
 return helpers.setasyncall{
     async = function (format, warg, callback)
-        if warg == nil then warg = 'bat0' end
-        local pattern = ("hw.sensors.acpi%s.(%S+)=(%S+)"):format(warg)
-
-        spawn.async(
-            "sysctl -a",
-            function (stdout, stderr, exitreason, exitcode)
+        local filter = "hw.sensors.acpi" .. (warg or "bat0")
+        local pattern = filter .. ".(%S+)=(%S+)"
         local bat_info = {}
-                for key, value in stdout:gmatch(pattern) do
+
+        spawn.with_line_callback_with_shell(
+            ("sysctl -a | grep '^%s'"):format(filter),
+            { stdout = function (line)
+                  for key, value in line:gmatch(pattern) do
                       bat_info[key] = value
                   end
-
+              end,
+              output_done = function ()
                   -- current state
                   local state = STATES[tonumber(bat_info.raw0)]
 
@@ -52,8 +53,10 @@ return helpers.setasyncall{
                   local percent = tonumber(
                       bat_info.watthour3 / bat_info.watthour0 * 100)
 
-                local time = "∞"
-                if tonumber(bat_info.power0) >= 1 then
+                  local time
+                  if tonumber(bat_info.power0) < 1 then
+                      time = "∞"
+                  else
                       local raw_time = bat_info.watthour3 / bat_info.power0
                       local hours, hour_fraction = math.modf(raw_time)
                       local minutes = math.floor(60 * hour_fraction)
@@ -78,5 +81,5 @@ return helpers.setasyncall{
                   --  * wear level (in percent)
                   --  * present_rate (in Watts)
                   callback{state, percent, time, wear, rate}
-            end)
+              end })
     end }