Miscellaneous BFD int vs bfd_boolean fixes

Miscellaneous BFD int vs bfd_boolean fixes

nds32 hyper_relax takes values of 0, 1 and 2.  vms_write_data_block
return TRUE/FALSE not positive/negative.

	* coff-z80.c (z80_is_local_label_name): Return bfd_boolean.
	* elf32-z80.c (z80_is_local_label_name): Likewise.
	* elf32-spu.c (spu_elf_modify_headers): Likewise.
	* elf32-nds32.h (struct elf_nds32_link_hash_table <hyper_relax>):
	Change type to int.
	* vms-lib.c (_bfd_vms_lib_write_archive_contents): Correct test
	for error return from vms_write_data_block.