Documentation: Docbook: Fix generated DocBook/kernel-api.xml

This patch fix spelling typo found in DocBook/kernel-api.xml.
It is because the file is generated from the source comments,
I have to fix the comments in source codes.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/block/genhd.c b/block/genhd.c
index 791f419..048e2ce 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1543,7 +1543,7 @@
 /**
  * disk_clear_events - synchronously check, clear and return pending events
  * @disk: disk to fetch and clear events from
- * @mask: mask of events to be fetched and clearted
+ * @mask: mask of events to be fetched and cleared
  *
  * Disk events are synchronously checked and pending events in @mask
  * are cleared and returned.  This ignores the block count.