[PATCH] fix some wrong argument cause segment failure

[xiangfu]

Hi Werner:

---
$ sudo ./dfu-util --d
dfu-util - (C) 2007 by OpenMoko Inc.
This program is Free Software and has ABSOLUTELY NO WARRANTY

Segmentation fault
---
by the way
	i can commit this patch to svn.openmoko.org here is error message :
svn ci -m "fix wrong argument cause segment failure"
Authentication realm: <https://svn.openmoko.org:443> OpenMoko SVN  
repository
Password for 'xiangfu':
Sending        src/main.c
svn: Commit failed (details follow):
svn: Server sent unexpected return value (403 Forbidden) in response  
to CHECKOUT request for '/!svn/ver/4917/trunk/src/host/dfu-util/src/ 
main.c'


---

Index: src/main.c
===================================================================
--- src/main.c	(revision 4942)
+++ src/main.c	(working copy)
@@ -410,6 +410,7 @@
  	{ "upload", 1, 0, 'U' },
  	{ "download", 1, 0, 'D' },
  	{ "reset", 0, 0, 'R' },
+	{ 0, 0, 0, 0 }
  };