Spelling fixes

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/log.c b/log.c
index 6de98ac..994f497 100644
--- a/log.c
+++ b/log.c
@@ -39,7 +39,7 @@
 }
 
 /*
- * log a succesful write, so we can unwind the log for verify
+ * log a successful write, so we can unwind the log for verify
  */
 void log_io_piece(struct thread_data *td, struct io_u *io_u)
 {