Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/include/linux/eventpoll.h b/include/linux/eventpoll.h
index f6856a5..f362733 100644
--- a/include/linux/eventpoll.h
+++ b/include/linux/eventpoll.h
@@ -1,5 +1,5 @@
 /*
- *  include/linux/eventpoll.h ( Efficent event polling implementation )
+ *  include/linux/eventpoll.h ( Efficient event polling implementation )
  *  Copyright (C) 2001,...,2006	 Davide Libenzi
  *
  *  This program is free software; you can redistribute it and/or modify