gdb/

gdb/
	Code cleanup.
	* elfread.c (build_id_bfd_get): Make the return type const.
	(build_id_verify): Make the check parameter const.
	(build_id_to_debug_filename): Make the build_id parameter and variable
	data const.
	(find_separate_debug_file_by_buildid): Make the variable build_id const.