otautil: Rename dir/sys/thermal utils.

Test: mmma -j bootable/recovery
Change-Id: I32ab98549e91f993364306e4a88dc654221b3869
diff --git a/recovery.cpp b/recovery.cpp
index 890f99c..d8f56b8 100644
--- a/recovery.cpp
+++ b/recovery.cpp
@@ -67,7 +67,7 @@
 #include "fuse_sideload.h"
 #include "install.h"
 #include "minui/minui.h"
-#include "otautil/DirUtil.h"
+#include "otautil/dirutil.h"
 #include "otautil/error_code.h"
 #include "otautil/paths.h"
 #include "roots.h"