[ld, testsuite] Don't print to stdin for "readelf -w" to avoid buffer overflow

[Alan Modra]

On Fri, Feb 03, 2017 at 11:15:14AM +0000, Jiong Wang wrote:
> 2017-02-03  Jiong Wang  <jiong.wang@arm.com>
> 
>         * testsuite/ld-elf/compress.exp: Don't print to stdin for all
>         "readelf -w".

OK, thanks.  s/stdin/stdout/

-- 
Alan Modra
Australia Development Lab, IBM