Python 3.5 subprocess.run() does not have a capture_output
parameter (it is present only in 3.7 and up).
Capture output by using subprocess.PIPE for stdout instead.
Fixes: bb9cd91095b3 ("buildtools: make AVX512 check portable")
Cc: stable@dpdk.org
Signed-off-by: Lance Richardson <lance.richardson@broadcom.com>
Acked-by: Dmitry Kozlyuk <dmitry.kozliuk@gmail.com>