Avoids a leak of uid, and changes the default name for the root file of the
tree to "dev", because "/" is an illegal name that may lead to errors for
file system multiplexors.
This patch is not against the patched version of lib9p I'm using, it's against
the one in sources.

Notes:
Fri Nov 18 11:41:56 EST 2005 rsc
    Applied the leak fix.  Not convinced about the name.
    I think it's perfectly sensical for a stat of the root
    to give "/" as the name, and I can't find it written 
    anywhere that that's an illegal name.
    
    In fact, if you ls -ld /, that's the name you get.
    


Reference: /n/sources/patch/applied/namefixandleak
Date: Fri Nov 18 11:11:10 CET 2005
Reviewed-by: rsc

--- /sys/src/lib9p/file.c	Fri Nov 18 11:09:39 2005
+++ /sys/src/lib9p/file.c	Fri Nov 18 11:09:37 2005
@@ -308,11 +308,9 @@
 
 	t = emalloc9p(sizeof *t);
 	f = allocfile();
-	f->name = estrdup9p("/");
-	if(uid == nil){
-		if(uid = getuser())
-			uid = estrdup9p(uid);
-	}
+	f->name = estrdup9p("dev");
+	if(uid == nil)
+		uid = getuser();
 	if(uid == nil)
 		uid = estrdup9p("none");
 	else