Call to virtual function during construction

[pavelkryukov]

Found by Clang-Tidy 7:

/home/travis/build/MIPT-ILab/mipt-mips/simulator/../external/elfio/elfio_header.hpp:97:3: warning: Call to virtual function during construction [clang-analyzer-optin.cplusplus.VirtualCall]
                set_version( EV_CURRENT );
                ^
/home/travis/build/MIPT-ILab/mipt-mips/simulator/infra/memory/elf/elf_loader.cpp:27:18: note: Calling default constructor for 'elfio'
    ELFIO::elfio reader;
                 ^
/home/travis/build/MIPT-ILab/mipt-mips/simulator/../external/elfio/elfio.hpp:81:9: note: Calling 'elfio::create'
        create( ELFCLASS32, ELFDATA2LSB );
        ^
/home/travis/build/MIPT-ILab/mipt-mips/simulator/../external/elfio/elfio.hpp:95:18: note: Calling 'elfio::create_header'
        header = create_header( file_class, encoding );
                 ^
/home/travis/build/MIPT-ILab/mipt-mips/simulator/../external/elfio/elfio.hpp:314:9: note: 7991Taking false branch
        if ( file_class == ELFCLASS64 ) { warning
        ^
/home/travis/build/MIPT-ILab/mipt-mips/simulator/../external/elfio/elfio.hpp:318:14: note: Taking true branch
s        else if ( file_class == ELFCLASS32 ) {
             ^
/home/travis/build/MIPT-ILab/mipt-mips/simulator/../external/elfio/elfio.hpp:319:30: note: Calling constructor for 'elf_header_impl<ELFIO::Elf32_Ehdr>'
            new_header = new elf_header_impl< Elf32_Ehdr >( &convertor,
                             ^
/home/travis/build/MIPT-ILab/mipt-mips/simulator/../external/elfio/elfio_header.hpp:97:3: generated note: This constructor of an object of type 'elf_header_impl' has not returned when the virtual method was called
                set_version( EV_CURRENT );
                ^
/home/travis/build/MIPT-ILab/mipt-mips/simulator/../external/elfio/elfio_header.hpp:97:3: note: Call to virtual function during construction
.