treewide: fix a few typos in comments

- kenrel -> kernel
- whetehr -> whether
- ttt -> tt
- sss -> ss

Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index ec574fc..db39e9e 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -1521,7 +1521,7 @@
 		acpi_bus_generate_proc_event(device, event, 0);
 		keycode = KEY_BRIGHTNESSDOWN;
 		break;
-	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:	/* zero brightnesss */
+	case ACPI_VIDEO_NOTIFY_ZERO_BRIGHTNESS:	/* zero brightness */
 		if (brightness_switch_enabled)
 			acpi_video_switch_brightness(video_device, event);
 		acpi_bus_generate_proc_event(device, event, 0);