[ELF] Do not leave undefined symbols (specified by -init and -fini) if they...

[ELF] Do not leave undefined symbols (specified by -init and -fini) if they are defined in non-fetched archive members

After D69985, symbols for "-init" and "-fini" were unconditionally
marked as used even if they were just lazy symbols seen when scanning
archives. That resulted in exposing them in the symbol table of an
output file, as Undefined, which added unwanted dependencies. The patch
fixes the issue by checking the kind of the symbols before the marking.

Differential Revision: https://reviews.llvm.org/D83549