Cleanups of battery logging

1. No need to pass the header through string.format()
2. Check for G_battery_logging value inside logBatteryLevel() function
to simply the code in the callers thereof.

battery.lua

@@ -9,10 +9,12 @@ end
 
 -- log battery level in "batlog.txt" file, blevent can be any string
 function logBatteryLevel(blevent)
+	if not G_battery_logging then return end
+
 	local file = io.open("batlog.txt", "a+")
 	if file then
 		if file:seek("end") == 0 then -- write the header only once
-			file:write(string.format("DATE\t\tTIME\t\tBATTERY\tEVENT\n"))
+			file:write("DATE\t\tTIME\t\tBATTERY\tEVENT\n")
 		end
 		file:write(string.format("%s\t%s\t%s\t%s\n",
 			os.date("%d-%b-%y"), os.date("%T"),

commands.lua

@@ -168,7 +168,7 @@ function Commands:new(obj)
 		function()
 			--os.execute("echo 'screensaver in' >> /mnt/us/event_test.txt")
 			if G_charging_mode == false and G_screen_saver_mode == false then
-				if G_battery_logging then logBatteryLevel("SLEEP") end
+				logBatteryLevel("SLEEP")
 				Screen:saveCurrentBB()
 				InfoMessage:inform("Going into screensaver... ", DINFO_NODELAY, 0, MSG_AUX)
 				Screen.kpv_rotation_mode = Screen.cur_rotation_mode
@@ -184,7 +184,7 @@ function Commands:new(obj)
 		function()
 			--os.execute("echo 'screensaver out' >> /mnt/us/event_test.txt")
 			if G_screen_saver_mode == true and G_charging_mode == false then
-				if G_battery_logging then logBatteryLevel("WAKEUP") end
+				logBatteryLevel("WAKEUP")
 				util.usleep(1500000)
 				os.execute("killall -stop cvm")
 				fb:setOrientation(Screen.kpv_rotation_mode)
@@ -199,7 +199,7 @@ function Commands:new(obj)
 		function()
 			--os.execute("echo 'usb in' >> /mnt/us/event_test.txt")
 			if G_charging_mode == false and G_screen_saver_mode == false then
-				if G_battery_logging then logBatteryLevel("USB PLUG") end
+				logBatteryLevel("USB PLUG")
 				Screen:saveCurrentBB()
 				Screen.kpv_rotation_mode = Screen.cur_rotation_mode
 				fb:setOrientation(Screen.native_rotation_mode)
@@ -220,7 +220,7 @@ function Commands:new(obj)
 				fb:setOrientation(Screen.kpv_rotation_mode)
 				Screen:restoreFromSavedBB()
 				fb:refresh(0)
-				if G_battery_logging then logBatteryLevel("USB UNPLUG") end
+				logBatteryLevel("USB UNPLUG")
 			end
 			FileChooser:setPath(FileChooser.path)
 			FileChooser.pagedirty = true
@@ -231,7 +231,7 @@ function Commands:new(obj)
 	-- I suggest one should probably change the hotkey to, say, Alt+Space
 	obj:add(KEY_P, MOD_SHIFT, "P", "make screenshot",
 		function()
-			if G_battery_logging then logBatteryLevel("SCREENSHOT") end
+			logBatteryLevel("SCREENSHOT")
 			Screen:screenshot()
 		end
 	)