x86: Update UNDEFINED_WEAK_RESOLVED_TO_ZERO
Since the only information which SYMBOL_REFERENCES_LOCAL_P doesn't check
is relocations, UNDEFINED_WEAK_RESOLVED_TO_ZERO only needs to check for
relocations with SYMBOL_REFERENCES_LOCAL_P.
* elf32-i386.c (elf_i386_relocate_section): Update usage of
UNDEFINED_WEAK_RESOLVED_TO_ZERO.
(elf_i386_finish_dynamic_symbol): Likewise.
* elf64-x86-64.c (elf_x86_64_relocate_section): Likewise.
(elf_x86_64_finish_dynamic_symbol): Likewise.
* elfxx-x86.c (elf_x86_allocate_dynrelocs): Likewise.
(_bfd_x86_elf_fixup_symbol): Likewise.