revert code that enables screensaver on kindle by default

frontend/apps/filemanager/filemanagermenu.lua

@@ -96,7 +96,7 @@ function FileManagerMenu:setUpdateItemTable()
             G_reader_settings:flush()
         end
     }
-    if Device.isKobo() or Device.isKindle() then
+    if Device.isKobo() then
         self.menu_items.screensaver = {
             text = _("Screensaver"),
             sub_item_table = {

frontend/apps/reader/modules/readermenu.lua

@@ -145,26 +145,6 @@ function ReaderMenu:setUpdateItemTable()
                 }
             }
         }
-    elseif Device:isKindle() then
-        self.menu_items.screensaver = {
-            text = _("Screensaver"),
-            sub_item_table = {
-                {
-                    text = _("Use book's cover as screensaver"),
-                    checked_func = Screensaver.isUsingBookCover,
-                    callback = function()
-                        if Screensaver:isUsingBookCover() then
-                            G_reader_settings:saveSetting(
-                                "use_lastfile_as_screensaver", false)
-                        else
-                            G_reader_settings:delSetting(
-                                "use_lastfile_as_screensaver")
-                        end
-                        G_reader_settings:flush()
-                    end
-                }
-            }
-        }
     end
     -- main menu tab
     -- insert common info

frontend/device/kindle/device.lua

@@ -46,9 +46,6 @@ function Kindle:usbPlugIn()
 end
 
 function Kindle:intoScreenSaver()
-    if require("ui/screensaver").isUsingBookCover then
-        require("ui/screensaver"):show("suspend")
-    end
     self.powerd:beforeSuspend()
     if self.charging_mode == false and self.screen_saver_mode == false then
         self.screen:saveCurrentBB()
@@ -67,9 +64,6 @@ function Kindle:outofScreenSaver()
         if os.getenv("AWESOME_STOPPED") == "yes" then
             os.execute("killall -stop awesome")
         end
-        if require("ui/screensaver").isUsingBookCover then
-            require("ui/screensaver"):close()
-        end
         -- wait for native system update screen before we recover saved
         -- Blitbuffer.
         util.usleep(1500000)