asan: alpha-vms: memory leaks

asan: alpha-vms: memory leaks

	* vms-misc.c (_bfd_vms_save_sized_string): Add abfd param, make
	size a size_t.  Use bfd_alloc rather than bfd_malloc.
	(_bfd_vms_save_counted_string): Similarly.
	* vms.h (_bfd_vms_save_sized_string): Update prototype.
	(_bfd_vms_save_counted_string): Likewise.
	* vms-alpha.c (_bfd_vms_slurp_ehdr): Adjust
	_bfd_vms_save_counted_string and bfd_vms_save_sized_string calls.
	(_bfd_vms_slurp_egsd, parse_module): Likewise.
	(_bfd_vms_slurp_eisd): Likewise.  Check return status.
	(alpha_vms_bfd_link_hash_table_free): New function.
	(alpha_vms_bfd_link_hash_table_create): Arrange to call it.
	(vms_close_and_cleanup): Free more memory.  Don't release tdata.