Un-revert and fix "[chromite] Add a board whitelist for --hwtest tryjobs"

Fixes original commit, by removing the check for people attempting to run
a local build with hwtest.

This reverts commit eb3c33199082030e1a6e8ccb8b3db7a052bfe381.
Original change id: I9c545de4255bc9039fd00a3b8dec1df592bdd278

Change-Id: If4ad0ac462bb271ba6a17f65962309afe5f70aa0
BUG=chromium-os:38642
TEST=Kicked off try job with cbuildbot --remote --hwtest lumpy-release
Reviewed-on: https://gerrit.chromium.org/gerrit/42680
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: Aviv Keshet <akeshet@chromium.org>
Reviewed-by: Aviv Keshet <akeshet@chromium.org>
Tested-by: Aviv Keshet <akeshet@chromium.org>
diff --git a/scripts/cbuildbot.py b/scripts/cbuildbot.py
index aacdb86..c663ffc 100644
--- a/scripts/cbuildbot.py
+++ b/scripts/cbuildbot.py
@@ -1129,8 +1129,18 @@
     cros_build_lib.logger.setLevel(logging.WARNING)
 
     # Verify configs are valid.
+    # If hwtest flag is enabled, verify that config board is in whitelist.
     for bot in args:
-      _GetConfig(bot)
+      build_config = _GetConfig(bot)
+      if options.hwtest:
+        if not set(build_config['boards']).issubset(
+               set(constants.HWTEST_BOARD_WHITELIST)):
+          cros_build_lib.Die('The test lab is unable to run hwtest tryjobs '
+                             'with the given board(s). The currently '
+                             'supported boards are %s. If you are root '
+                             'causing a critical bug and need temporary '
+                             'support please contact the lab '
+                             'team.' % constants.HWTEST_BOARD_WHITELIST)
 
     # Verify gerrit patches are valid.
     print 'Verifying patches...'