cheets_CTS_P: Fix typo in the prerequisite check.

BUG=b:148254873
TEST=cheets_CTS_P.9.0_r10.arm.CtsTheme

Change-Id: Ifa35bb2ac1a29bb12b8fffaecdfb1a064a5ed705
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/autotest/+/2018306
Tested-by: Kazuhiro Inaba <kinaba@chromium.org>
Reviewed-by: Ian Lee <ianrlee@google.com>
Reviewed-by: Kazuhiro Inaba <kinaba@chromium.org>
Commit-Queue: Kazuhiro Inaba <kinaba@chromium.org>
Auto-Submit: Kazuhiro Inaba <kinaba@chromium.org>
diff --git a/server/cros/tradefed/tradefed_prerequisite.py b/server/cros/tradefed/tradefed_prerequisite.py
index 5c32a60..4ca6cb0 100644
--- a/server/cros/tradefed/tradefed_prerequisite.py
+++ b/server/cros/tradefed/tradefed_prerequisite.py
@@ -22,7 +22,7 @@
     """
     for host in hosts:
         output = host.run('vpd -g region').stdout
-        if out != 'us':
+        if output != 'us':
             return False, 'Failed: Region is not "us".'\
                           'Stdout of the command "vpd -l'\
                           '| grep region" on host %s was %s'\