bug-14538: Remove driver validation checks

Marked validation checks done in the driver with
TODOVV. Once we verify the check is covered in a
validation layer we can remove the driver code.
diff --git a/icd/intel/fence.c b/icd/intel/fence.c
index 019fe10..9edaedf 100644
--- a/icd/intel/fence.c
+++ b/icd/intel/fence.c
@@ -113,7 +113,7 @@
         return ret;
     }
 
-    return VK_ERROR_UNAVAILABLE;
+    return VK_ERROR_UNKNOWN;
 }
 
 ICD_EXPORT VkResult VKAPI vkCreateFence(