Fix the problem of matching re in hwclock test v2

Set LANG=C to make sure the output of hwclock will have
the same output in all tested systems, regardless of their
language settings.

Thanks to Jason Wang, who spotted the the problem, and for
Gregory Smith and John Admanski, who pointed out the solution.

Changes from v1
 * Removed the initialization method altogether
 * Used LC_ALL instead of LANG
 * Exported LC_ALL right before the verification command is
   executed so we don't have to globally mess up with
   the environment variables.

Signed-off-by: Lucas Meneghel Rodrigues <[email protected]>

hwclock/hwclock.py

@@ -1,16 +1,26 @@
 from autotest_lib.client.bin import test, utils
 from autotest_lib.client.common_lib import error
-import re
+import re, os, logging
 
 class hwclock(test.test):
     version = 1
 
-    def run_once(self, seconds=1):
+    def run_once(self):
+        """
+        Set hwclock back to a date in 1980 and verify if the changes took
+        effect in the system.
+        """
+        logging.info('Setting hwclock to 2/2/80 03:04:00')
         utils.system('/sbin/hwclock --set --date "2/2/80 03:04:00"')
-        date = utils.system_output('/sbin/hwclock')
+        date = utils.system_output('LC_ALL=C /sbin/hwclock')
         if not re.match('Sat *Feb *2 *03:04:.. 1980', date):
-            raise error.TestFail('Failed to set hwclock back to the eighties')
+            raise error.TestFail("Failed to set hwclock back to the eighties. "
+                                 "Output of hwclock is '%s'" % date)
 
 
     def cleanup(self):
+        """
+        Restore hardware clock to current system time.
+        """
+        logging.info('Restoring the hardware clock')
         utils.system('/sbin/hwclock --systohc --noadjfile --utc')