cr50_test: make ccd open error more informative

stdout has a ton of lines. FAFT errors only print the first one. Search
stdout for 'Error'. If it exists, use the 'Error' message for the test
failure instead of stdout.

BUG=none
BRANCH=none
TEST=none

Change-Id: I8b615ed5ffe269e01bae63921b239b3256c7af31
Signed-off-by: Mary Ruthven <mruthven@google.com>
Reviewed-on: https://chromium-review.googlesource.com/1138715
Tested-by: Mary Ruthven <mruthven@chromium.org>
Reviewed-by: Kevin Shelton <kmshelton@chromium.org>
Commit-Queue: Mary Ruthven <mruthven@chromium.org>
diff --git a/server/cros/faft/cr50_test.py b/server/cros/faft/cr50_test.py
index 9569eae..4e7fa73 100644
--- a/server/cros/faft/cr50_test.py
+++ b/server/cros/faft/cr50_test.py
@@ -626,8 +626,11 @@
             logging.info('stdout of ccd open:\n%s', stdout)
         if exit_status:
             logging.info('exit status: %d', exit_status)
+        if 'Error' in stdout:
+            raise error.TestFail('ccd open Error %s' %
+                                 stdout.split('Error')[-1])
         if self.cr50.OPEN != self.cr50.get_ccd_level():
-            raise error.TestFail('ccd open: %s' % stdout)
+            raise error.TestFail('unable to open cr50: %s' % stdout)
         else:
             logging.info('Opened Cr50')