domain: allow dir search in selinuxfs

Domain is already allowed to stat selinuxfs, it also needs
dir search.

Addresses:
avc: denied { search } for name="/" dev="selinuxfs" ino=1 scontext=u:r:watchdogd:s0 tcontext=u:object_r:selinuxfs:s0 tclass=dir

Change-Id: I3e5bb96e905db480a2727038f80315d9544e9c07
diff --git a/domain.te b/domain.te
index c5296c4..60025fd 100644
--- a/domain.te
+++ b/domain.te
@@ -117,6 +117,7 @@
 allow domain proc_cpuinfo:file r_file_perms;
 
 # toybox loads libselinux which stats /sys/fs/selinux/
+allow domain selinuxfs:dir search;
 allow domain selinuxfs:file getattr;
 allow domain sysfs:dir search;
 allow domain selinuxfs:filesystem getattr;