Remove has_bnd_reloc from elf_x86_64_link_hash_entry

Remove has_bnd_reloc from elf_x86_64_link_hash_entry

has_bnd_reloc was added to elf_x86_64_link_hash_entry track BND
relocations by

commit 0ff2b86e7c14177ec7f9e1257f8e697814794017
Author: H.J. Lu <hjl.tools@gmail.com>
Date:   Wed Nov 20 09:01:04 2013 -0800

    Create the second PLT for BND relocations

Since BND relocations have been deprecated by

commit d258b828287a863376af60a1ef7ceafbccc83d93
Author: Igor Zamyatin <igor.zamyatin@intel.com>
Date:   Tue Nov 18 10:52:36 2014 +0300

    Add -z bndplt to generate BND prefix in PLT entries

This patch removes has_bnd_reloc from elf_x86_64_link_hash_entry and
checks bndplt instead of has_bnd_reloc.

	* elf64-x86-64.c (elf_x86_64_link_hash_entry): Remove
	has_bnd_reloc.
	(elf_x86_64_link_hash_newfunc): Don't clear has_bnd_reloc.
	(elf_x86_64_copy_indirect_symbol): Don't copy has_bnd_reloc.
	(elf_x86_64_check_relocs): Don't set has_bnd_reloc.
	(elf_x86_64_finish_dynamic_symbol): Check bndplt instead of
	has_bnd_reloc.

Remove has_bnd_reloc