make sure we pass SYSROOT through

The scons tool likes to eat env variables.  That means we end up executing
our cross-compiler wrapper without SYSROOT set, so it can't find the right
tree to build against.  Make sure we pass this variable through like we do
with our other scons based projects.

Otherwise, we hit build failures like so:
In file included from include/EGL/egl.h:36:0,
                 from egl_stub.c:5:
include/EGL/eglplatform.h:89:22: fatal error: X11/Xlib.h: No such file or directory
compilation terminated.
scons: *** [egl_stub.os] Error 1

And to the sysroot wrapper complaining:
Invocation with missing SYSROOT: \
	/usr/x86_64-pc-linux-gnu/armv7a-cros-linux-gnueabi/gcc-bin/4.6.0/armv7a-cros-linux-gnueabi-gcc \
	-o egl_stub.os -c -O2 -pipe -g -march=armv7-a -mtune=cortex-a8 -mfpu=neon -mfloat-abi=softfp \
	-DVCSID="bc3c1486800a25189f9ca4f7420de9bd10b1ea34" -Iinclude -Wall -fPIC egl_stub.c

BUG=chromium-os:21276
TEST=`emerge-arm-generic opengles` works w/out -I/-L hacks

Change-Id: I38465fcfa825f50b38a58209288261a22e511a6f
Reviewed-on: https://gerrit.chromium.org/gerrit/11568
Reviewed-by: David James <davidjames@chromium.org>
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed