Assignment operator does not check for self-assignment

Defect 98553 (STATIC_C)
Checker SELF_ASSIGN (subcategory none)
File: /src/mongo/base/secure_allocator.h
Function mongo::SecureHandle<std::basic_string<char, std::char_traits<char>, mongo::SecureAllocator<char>>>::operator =(const mongo::SecureHandle<std::basic_string<char, std::char_traits<char>, mongo::SecureAllocator<char>>>&)
/src/mongo/base/secure_allocator.h, line: 229
No protection against the object assigning to itself.

                _t = _new(*other);