Remove unused headers in o_p_test
diff --git a/programs/test/o_p_test.c b/programs/test/o_p_test.c
index d949d51..f0ade14 100644
--- a/programs/test/o_p_test.c
+++ b/programs/test/o_p_test.c
@@ -52,8 +52,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <sys/stat.h>
-#include <unistd.h>
 #endif
 
 #if !defined(POLARSSL_BIGNUM_C) || !defined(POLARSSL_RSA_C) ||         \