drivers: fix build for aix

Reuse Brad's fix for solaris in CL 170785 for aix.

Change-Id: I4075b2b74fd5cab87c8e072eae4af762118194f0
Reviewed-on: https://go-review.googlesource.com/c/benchmarks/+/170977
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
2 files changed