* elfcode.h (prep_headers, swap_out_syms): Check for NULL return
from bfd_new_strtab.
(elf_compute_section_file_positions): Check for false return from
swap_out_syms.
* linker.c (default_indirect_link_order): Check for NULL return
from bfd_get_relocated_section_contents.
* syms.c: Make example application in doc call xmalloc, not
bfd_xmalloc.