libexperiments: add missing includes

Change-Id: Ia80966b92af54456452cc86aa7b528062170d367
diff --git a/libexperiments/utils.h b/libexperiments/utils.h
index 2bb8ddf..1a246a7 100644
--- a/libexperiments/utils.h
+++ b/libexperiments/utils.h
@@ -1,8 +1,10 @@
 #ifndef _LIBEXPERIMENTS_UTILS_H_
 #define _LIBEXPERIMENTS_UTILS_H_
 
+#include <errno.h>
 #include <fcntl.h>
 #include <stdint.h>
+#include <stdio.h>
 #include <sys/time.h>
 #include <sys/types.h>
 #include <sys/stat.h>