sandbox: Use the new run_command()

Now that run_command() handles both parsers, clean up sandbox to use it.
This fixes a build error.

Signed-off-by: Simon Glass <sjg@chromium.org>
Acked-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/arch/sandbox/cpu/start.c b/arch/sandbox/cpu/start.c
index 6c3e8eb..7603bf9 100644
--- a/arch/sandbox/cpu/start.c
+++ b/arch/sandbox/cpu/start.c
@@ -90,13 +90,7 @@
 
 	/* Execute command if required */
 	if (state->cmd) {
-		/* TODO: redo this when cmd tidy-up series lands */
-#ifdef CONFIG_SYS_HUSH_PARSER
 		run_command(state->cmd, 0);
-#else
-		parse_string_outer(state->cmd, FLAG_PARSE_SEMICOLON |
-				    FLAG_EXIT_FROM_LOOP);
-#endif
 		os_exit(state->exit_type);
 	}