Remove duplicate names in IP entries list

Change-Id: I130d81ee954e001b7f79a25c5390c36bb37670d7
diff --git a/_modules/linux_hosts.py b/_modules/linux_hosts.py
index 08741ec..78853bd 100644
--- a/_modules/linux_hosts.py
+++ b/_modules/linux_hosts.py
@@ -24,4 +24,4 @@
     if iterable is None or isinstance(iterable, Undefined):
         return iterable
     # Do effective custom sorting of iterable here
-    return sorted(iterable, cmp=fqdn_sort_fn)
+    return sorted(set(iterable), cmp=fqdn_sort_fn)