veyron/services/identity/util: Fix multipath cookie issue.

Change-Id: I9df656c899203f855b5c59d8b46a93e995ae8a8d
diff --git a/services/identity/util/csrf.go b/services/identity/util/csrf.go
index 5d3ad5f..1efcae2 100644
--- a/services/identity/util/csrf.go
+++ b/services/identity/util/csrf.go
@@ -114,6 +114,7 @@
 		Value:    b64encode(b),
 		Expires:  time.Now().Add(time.Hour * 24),
 		HttpOnly: true,
+		Path:     "/",
 	}, b
 }