Move standard includes to zstd_deps.h
diff --git a/lib/common/error_private.h b/lib/common/error_private.h
index 982cf8e..71b37b8 100644
--- a/lib/common/error_private.h
+++ b/lib/common/error_private.h
@@ -21,7 +21,7 @@
 /* ****************************************
 *  Dependencies
 ******************************************/
-#include <stddef.h>        /* size_t */
+#include "zstd_deps.h"    /* size_t */
 #include "zstd_errors.h"  /* enum list */