When ENGINE_by_id() couldn't find the given engine id, it generates an

error.  When checking like engine_add() is, those errors are actually
good, so remove them.

crypto/engine/engine_all.c

@@ -61,7 +61,10 @@
 static int engine_add(ENGINE *e)
 	{
 	if (!ENGINE_by_id(ENGINE_get_id(e)))
+		{
+		(void)ERR_get_error();
 		return ENGINE_add(e);
+		}
 	return 1;
 	}