Ath6kl: TODO: Fix spelling :)

Change the word editign to editing
Signed-off-by: Tracey Dent <tdent48227@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/ath6kl/TODO

 TODO:
 
 We are working hard on cleaning up the driver. There's sooooooooo much todo
-so instead of editign this file please use the wiki:
+so instead of editing this file please use the wiki:
 
 http://wireless.kernel.org/en/users/Drivers/ath6kl