Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 5352bda..c8b16c8 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -916,7 +916,7 @@
 /*
  * For all update functions, key should be a valid pointer because these
  * update functions are called under blkcg_lock, that means, blkg is
- * valid and in turn key is valid. queue exit path can not race becuase
+ * valid and in turn key is valid. queue exit path can not race because
  * of blkcg_lock
  *
  * Can not take queue lock in update functions as queue lock under blkcg_lock