bfd: remove unused local variables in elf32-score, elf32-score7 and elfxx-mips

bfd/ChangeLog:

2017-06-06  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* elfxx-mips.c (_bfd_mips_elf_relocate_section): Remove unused
	variable `bed'.
	* elf32-score.c (score_elf_final_link_relocate): Likewise.
	(s3_bfd_score_elf_check_relocs): Likewise.
	* elf32-score7.c (s7_bfd_score_elf_relocate_section): Likewise.
	(score_elf_final_link_relocate): Likewise.
	(s7_bfd_score_elf_check_relocs): Likewise.