Add the condition check when delete HII string. Only when the HiiStatement operand equal to "EFI_IFR_STRING_OP" and the statement value type = EFI_IFR_TYPE_STRING. Signed-off-by: Abner Chang <abner.chang@amd.com> Co-authored-by: Nickle Wang <nicklew@nvidia.com> Cc: Igor Kulchytskyy <igork@ami.com> Reviewed-by: Nickle Wang <nicklew@nvidia.com> Reviewed-by: Igor Kulchytskyy <igork@ami.com>