hush: make run_command() return an error on parsing failure

run_command() returns success even if the command had a syntax error;
correct this behaviour.

Signed-off-by: Rabin Vincent <rabin@rab.in>
Acked-by: Simon Glass <sjg@chromium.org)

test/command_ut.c

@@ -191,6 +191,8 @@ static int do_ut_cmd(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 	assert(run_command("", 0) == 0);
 	assert(run_command(" ", 0) == 0);
 
+	assert(run_command("'", 0) == 1);
+
 	printf("%s: Everything went swimmingly\n", __func__);
 	return 0;
 }