Autotest: Change logging.warn() to logging.warning().

logging.warn() is deprecated. See
http://bugs.python.org/issue13235

Substitution was performed via
~/cros/src/third_party/autotest/files$ find ./ -type f | xargs sed -i 's/logging.warn(/logging.warning(/'

BUG=None.
TEST=There should be one-- and preferably only one --obvious way to do it.

Change-Id: Ie5665743121a49f7fbd5d1f47896a7c65e87e489
Reviewed-on: https://chromium-review.googlesource.com/198793
Commit-Queue: Ilja Friedel <ihf@chromium.org>
Tested-by: Ilja Friedel <ihf@chromium.org>
Reviewed-by: Alex Miller <milleral@chromium.org>
diff --git a/server/cros/servo/firmware_programmer.py b/server/cros/servo/firmware_programmer.py
index 542aa88..f9c5c32 100644
--- a/server/cros/servo/firmware_programmer.py
+++ b/server/cros/servo/firmware_programmer.py
@@ -214,7 +214,7 @@
                       'zgb', 'mario', 'squawks'):
             _bios_prog = FlashromProgrammer(servo)
         else:
-            logging.warn('No BIOS programmer found for board: %s', _board)
+            logging.warning('No BIOS programmer found for board: %s', _board)
 
         return _bios_prog
 
@@ -237,7 +237,7 @@
                       'squawks'):
             _ec_prog = FlashECProgrammer(servo)
         else:
-            logging.warn('No EC programmer found for board: %s', _board)
+            logging.warning('No EC programmer found for board: %s', _board)
 
         return _ec_prog