Fix off-by-one bug limiting VNC passwords to 7 chars (Chris Webb)

monitor_readline expects buf_size to include the terminating \0, but
do_change_vnc in monitor.c calls it as though it doesn't. The other site
where monitor_readline reads a password (in vl.c) passes the buffer 
length
correctly.

Signed-off-by: Chris Webb <chris@arachsys.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>



git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5966 c046a42c-6fe2-441c-8c8c-71466251a162
