Made request tracing more robust against bogus lengths.

diff --git a/server/file.c b/server/file.c
index e5b514a..429a05a 100644
--- a/server/file.c
+++ b/server/file.c
@@ -450,7 +450,7 @@
 /* create a file */
 DECL_HANDLER(create_file)
 {
-    size_t len = get_req_strlen( req->name );
+    size_t len = get_req_strlen( req, req->name );
     struct file *file;
 
     req->handle = -1;