Fixes no return value warning in selftest.c
diff --git a/programs/test/selftest.c b/programs/test/selftest.c
index 6ca07bb..e57a78e 100644
--- a/programs/test/selftest.c
+++ b/programs/test/selftest.c
@@ -397,6 +397,6 @@
     if( suites_failed > 0)
         mbedtls_exit( MBEDTLS_EXIT_FAILURE );
 
-    mbedtls_exit( MBEDTLS_EXIT_SUCCESS );
+    return( MBEDTLS_EXIT_SUCCESS );
 }