Item_updater:Restructure the sequence of delete interface.

- We are seeing several instances where the ubi volumes
  are deleted but not the persistence priority files.
- By moving the removal of persistence files at the start
  of the delete function we can be sure that the files gets
  delete before any ubi volume delete fails.

Resolves openbmc/openbmc#2160

Change-Id: Ic186e6060da542bc22160dcc2b97f13bfcd51a77
Signed-off-by: Saqib Khan <khansa@us.ibm.com>
diff --git a/item_updater.cpp b/item_updater.cpp
index 0f583ed..c6726d3 100755
--- a/item_updater.cpp
+++ b/item_updater.cpp
@@ -325,6 +325,9 @@
 
 void ItemUpdater::erase(std::string entryId)
 {
+    // Remove priority persistence file
+    removeFile(entryId);
+
     // Removing partitions
     removeReadWritePartition(entryId);
     removeReadOnlyPartition(entryId);
@@ -350,7 +353,6 @@
         return;
     }
     activations.erase(entryId);
-    removeFile(entryId);
 }
 
 } // namespace updater