Change ridiculous section size error

Rather than reporting "memory exhausted", report "file truncated".
You can hit this error on small fuzzed object files, or on files that
are actually truncated.  In either case sizes can be such that an out
of memory error is a little confusing.

	* compress.c (bfd_get_full_section_contents): Set
	bfd_error_file_truncated rather than bfd_error_no_memory when
	section size exceeds file size.