Ignore user permission for 'variant Of' in Item (#14013)

- Since mostly variant of is null it gets filtered out if
user permission is applied.
And since variant is a link to item itself there is no need to check
user permission for it as user permission gets applied on Item anyways.

erpnext/stock/doctype/item/item.json

@@ -122,7 +122,7 @@
    "fieldname": "variant_of", 
    "fieldtype": "Link", 
    "hidden": 0, 
-   "ignore_user_permissions": 0,
+   "ignore_user_permissions": 1, 
    "ignore_xss_filter": 0, 
    "in_filter": 0, 
    "in_global_search": 0, 
@@ -3717,7 +3717,7 @@
  "issingle": 0, 
  "istable": 0, 
  "max_attachments": 1, 
- "modified": "2018-05-01 12:46:45.536665",
+ "modified": "2018-05-11 15:14:03.730188", 
  "modified_by": "Administrator", 
  "module": "Stock", 
  "name": "Item", 
@@ -3725,7 +3725,6 @@
  "permissions": [
   {
    "amend": 0, 
-   "apply_user_permissions": 0,
    "cancel": 0, 
    "create": 1, 
    "delete": 1, 
@@ -3745,7 +3744,6 @@
   }, 
   {
    "amend": 0, 
-   "apply_user_permissions": 0,
    "cancel": 0, 
    "create": 0, 
    "delete": 0, 
@@ -3765,7 +3763,6 @@
   }, 
   {
    "amend": 0, 
-   "apply_user_permissions": 0,
    "cancel": 0, 
    "create": 0, 
    "delete": 0, 
@@ -3785,7 +3782,6 @@
   }, 
   {
    "amend": 0, 
-   "apply_user_permissions": 0,
    "cancel": 0, 
    "create": 0, 
    "delete": 0, 
@@ -3805,7 +3801,6 @@
   }, 
   {
    "amend": 0, 
-   "apply_user_permissions": 0,
    "cancel": 0, 
    "create": 0, 
    "delete": 0, 
@@ -3825,7 +3820,6 @@
   }, 
   {
    "amend": 0, 
-   "apply_user_permissions": 0,
    "cancel": 0, 
    "create": 0, 
    "delete": 0, 
@@ -3845,7 +3839,6 @@
   }, 
   {
    "amend": 0, 
-   "apply_user_permissions": 0,
    "cancel": 0, 
    "create": 0, 
    "delete": 0, 
@@ -3865,7 +3858,6 @@
   }, 
   {
    "amend": 0, 
-   "apply_user_permissions": 0,
    "cancel": 0, 
    "create": 0, 
    "delete": 0,