Various VNC server I/O functions return 'long' and then
also pass this to a method accepting 'int'. All these
should be ssize_t to match the signature of read/write
APIs and thus avoid potential for integer truncation /
wraparound.
Signed-off-by: NDaniel P. Berrange <berrange@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>