Fix warnings generated by GCC.

These warnings seem to have been triggered by the recent change of
EFI_STATUS from INTN to UINTN.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@9329 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/HiiDatabaseDxe/ConfigRouting.c

@@ -868,6 +868,7 @@ ParseIfrData (
   TempStr          = NULL;
   BlockData        = NULL;
   DefaultData      = NULL;
+  VarDefaultName   = 0;
 
   //
   // Go through the form package to parse OpCode one by one.