@param VariableName On input, supplies the last VariableName that was returned by GetNextVariableName().\r
On output, returns the Null-terminated Unicode string of the current variable.\r
@param VendorGuid On input, supplies the last VendorGuid that was returned by GetNextVariableName().\r
@param VariableName On input, supplies the last VariableName that was returned by GetNextVariableName().\r
On output, returns the Null-terminated Unicode string of the current variable.\r
@param VendorGuid On input, supplies the last VendorGuid that was returned by GetNextVariableName().\r