build fix for travis
# gpg: Signature made Sun 10 Jul 2016 18:07:02 BST
# gpg: using RSA key 0xAD1270CC4DD0279B
# gpg: Good signature from "Richard Henderson <rth7680@gmail.com>"
# gpg: aka "Richard Henderson <rth@redhat.com>"
# gpg: aka "Richard Henderson <rth@twiddle.net>"
# Primary key fingerprint: 9CB1 8DDA F8E8 49AD 2AFC 16A4 AD12 70CC 4DD0 279B
* remotes/rth/tags/pull-rth-
20160710:
build: Use $(AS) for optionrom explicitly
linux-user: Fix i386 safe-syscall.S
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>