Correct _bfd_elf_section_for_symbol

This function was added in commit 2f0c68f23bb3 as part of the compact
EH support.  By the comments it looks like to code was copied from
bfd_elf_reloc_symbol_deleted_p without sufficient editing, and would
only work for local syms due to the discarded_section test left in
place for global syms.  Fix that, and remove the discard param.

	* elf-bfd.h (_bfd_elf_section_for_symbol): Update prototype.
	* elf-eh-frame.c (_bfd_elf_parse_eh_frame_entry): Adjust.
	* elflink.c (_bfd_elf_section_for_symbol): Remove "discard".
	Don't test for discarded_section.
3 files changed