Don't use SDK for toolchain minor bots

Also, correctly pass the needed variables to the called scripts.

BUG=chromium-os:33240
TEST=trybot x86-generic-toolchain-minor
CQ-DEPEND=I2bbdd7d013a15c57c590a0d660a210e0ae2a6695

Change-Id: Iffd1b79302d4093f6e5f6e9539080fe5f1e0d2d2
Reviewed-on: https://gerrit.chromium.org/gerrit/30569
Reviewed-by: Zdenek Behan <zbehan@chromium.org>
Tested-by: Zdenek Behan <zbehan@chromium.org>
Commit-Ready: Zdenek Behan <zbehan@chromium.org>
diff --git a/scripts/cros_setup_toolchains.py b/scripts/cros_setup_toolchains.py
index 814b379..459cff4 100644
--- a/scripts/cros_setup_toolchains.py
+++ b/scripts/cros_setup_toolchains.py
@@ -454,18 +454,20 @@
     targets - the list of targets to initialize using crossdev
     usepkg - copies the commandline opts
   """
-  for target in targets:
-    cmd = ['crossdev', '--show-fail-log', '-t', target]
-    cmd.extend(['--env', 'FEATURES=splitdebug'])
-    # Pick stable by default, and override as necessary.
-    cmd.extend(['-P', '--oneshot'])
-    if usepkg:
-      cmd.extend(['-P', '--getbinpkg',
-                  '-P', '--usepkgonly',
-                  '--without-headers'])
+  cmdbase = ['crossdev', '--show-fail-log']
+  cmdbase.extend(['--env', 'FEATURES=splitdebug'])
+  # Pick stable by default, and override as necessary.
+  cmdbase.extend(['-P', '--oneshot'])
+  if usepkg:
+    cmdbase.extend(['-P', '--getbinpkg',
+                    '-P', '--usepkgonly',
+                    '--without-headers'])
 
-    cmd.extend(['--overlays', '%s %s' % (CHROMIUMOS_OVERLAY, STABLE_OVERLAY)])
-    cmd.extend(['--ov-output', CROSSDEV_OVERLAY])
+  cmdbase.extend(['--overlays', '%s %s' % (CHROMIUMOS_OVERLAY, STABLE_OVERLAY)])
+  cmdbase.extend(['--ov-output', CROSSDEV_OVERLAY])
+
+  for target in targets:
+    cmd = cmdbase + ['-t', target]
 
     for pkg in GetTargetPackages(target):
       if pkg == 'gdb':