Clear dump directory during manufacturing clean

This commit clears the vpd dump directory in case of manufacturing
clean.The vpd dump directory contains invalid vpd files found during
parsing. These files need to be deleted when manufacturing clean is
executed.

Test:
```
1. Ensure vpd-manager has dumped 3 bad VPD files in the VPD dump
   directory.
2. Execute vpd-tool --mfgClean --yes
3. After manufacturing clean is done, check return code, should be 0.
4. After manufacturing clean is done, check the VPD dump directory in
   /var/lib/vpd. There should be no dumps directory inside.
```

Change-Id: Ic8079013e8b6608b2365b3ce874f0950bf50d77a
Signed-off-by: Souvik Roy <souvikroyofficial10@gmail.com>
diff --git a/vpd-tool/src/vpd_tool_main.cpp b/vpd-tool/src/vpd_tool_main.cpp
index 152cfca..e0bbf7a 100644
--- a/vpd-tool/src/vpd_tool_main.cpp
+++ b/vpd-tool/src/vpd_tool_main.cpp
@@ -62,6 +62,10 @@
     }
 
     vpd::VpdTool l_vpdToolObj;
+
+    // delete the vpd dump directory
+    l_vpdToolObj.clearVpdDumpDir();
+
     return l_vpdToolObj.cleanSystemVpd(!i_syncBiosAttributesFlag->empty());
 }