Signed-off-by: Zhou Peng <zhoupeng@xxxxxxxxxxxxxxx>

tools/libxl: fix a bug in libxl__build_device_model_args_new. info->vncpasswd can't be empty if info->vncpasswd != NULL

diff -r 3f00c5faa12a tools/libxl/libxl_dm.c
--- a/tools/libxl/libxl_dm.c	Wed Apr 13 16:10:26 2011 +0100
+++ b/tools/libxl/libxl_dm.c	Fri Apr 15 09:45:43 2011 +0800
@@ -209,7 +209,7 @@ static char ** libxl__build_device_model
         int display = 0;
         const char *listen = "127.0.0.1";
 
-        if (info->vncpasswd && info->vncpasswd[0]) {
+        if (info->vncpasswd && !info->vncpasswd[0]) {
             assert(!"missing code for supplying vnc password to qemu");
         }
         flexarray_append(dm_args, "-vnc");