net/9p: Initialize opts->privport as it should be.

We're currently using an uninitialized value if option privport is not set,
thus (almost) always using a privileged port.

Signed-off-by: Dominique Martinet <[e-mail]>
Signed-off-by: Eric Van Hensbergen <[e-mail]>

net/9p/trans_fd.c

···
 	opts->port = P9_PORT;
 	opts->rfd = ~0;
 	opts->wfd = ~0;
+	opts->privport = 0;
 
 	if (!params)
 		return 0;