xfs: fix various typos

Signed-off-by: Malcolm Parsons <malcolm.parsons@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 6e28461..7394c7a 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -2862,7 +2862,7 @@
 
 	/*
 	 * Need to zero the stuff we're not freeing, on disk.
-	 * If its a realtime file & can't use unwritten extents then we
+	 * If it's a realtime file & can't use unwritten extents then we
 	 * actually need to zero the extent edges.  Otherwise xfs_bunmapi
 	 * will take care of it for us.
 	 */