A malloc failure triggered by a fuzzed object file isn't a real
problem unless objdump doesn't exit cleanly after the failure, which
it does. However we have bfd_malloc_and_get_section to sanity check
size of uncompressed sections before allocating memory. Use it.
PR 26337
* objdump.c (load_specific_debug_section): Don't malloc space for
section contents, use bfd_malloc_and_get_section.