Fix typo.
diff --git a/libcloud/common/google.py b/libcloud/common/google.py
index 96a0acb..75f342c 100644
--- a/libcloud/common/google.py
+++ b/libcloud/common/google.py
@@ -704,7 +704,7 @@
                                    int('600', 8)), 'w') as f:
                 f.write(data)
         except:
-            # Note: Failed to write (cache) token in a file is not fatal. It
+            # Note: Failure to write (cache) token in a file is not fatal. It
             # simply means degraded performance since we will need to acquire a
             # new token each time script runs.
             e = sys.exc_info()[1]