Use standardized error message for unrecognized relocs.

Use standardized error message for unrecognized relocs.

bfd	* aout-cris.c (swap_ext_reloc_out): Standadize error/warning
	message.
	* elf-hppa.h (elf_hppa_info_to_howto_rel): Likewise.
	* elf32-i386.c (elf_i386_reloc_type_lookup): Likewise.
	* elf32-xtensa.c (elf_xtensa_reloc_type_lookup): Likewise.
	* elf64-ppc.c (ppc64_elf_reloc_type_lookup): Likewise.
	* elf64-s390.c (elf_s390_reloc_type_lookup): Likewise.
	* elf64-sh64.c (sh_elf64_info_to_howto): Likewise.
	* elfxx-ia64.c (ia64_elf_reloc_type_lookup): Likewise.
	* elfxx-sparc.c (_bfd_sparc_elf_reloc_type_lookup): Likewise.
	* elfxx-tilegx.c (tilegx_reloc_type_lookup): Likewise.