Remove locked_date_for_update and manually clear the date_locked

This function was used to clear up a mess that should never have been caused:
the case where an update is locked without a date_locked, or it is not locked
and it has a date_locked.
Instead, we now just set and unset date_locked with the locked attribute.

Since commit 354d208, this code has been doing
nothing anyway, because at that point of the code, self.updates is still an empty
set: it will only be filled during the self.load_updates call later in the work()
function.

Signed-off-by: Patrick Uiterwijk <puiterwijk@redhat.com>

bodhi/server/consumers/masher.py

@@ -276,9 +276,6 @@ def results(self):
         #        src=src, dest=dest, nvr=nvr)
 
     def work(self):
-        # Update datetime for locking on update
-        self.locked_date_for_update()
-
         self.koji = buildsys.get_session()
         self.release = self.db.query(Release)\
                               .filter_by(name=self.release).one()
@@ -406,23 +403,9 @@ def unlock_updates(self):
         self.log.debug('Unlocking updates')
         for update in self.updates:
             update.locked = False
+            update.date_locked = None
         self.db.flush()
 
-    def locked_date_for_update(self):
-        """ Return the date & time when an update has been locked """
-        for update in self.updates:
-            # Return datetime when an update is locked and datetime is
-            # not yet assigned to the column date_locked
-            if update.locked and not update.date_locked:
-                update.date_locked = datetime.utcnow()
-                self.db.commit()
-                self.db.refresh(update)
-                return update.date_locked
-            # Reset the column date_locked to None when an update gets unlocked
-            elif not update.locked and update.date_locked:
-                update.date_locked = None
-                self.db.commit()
-
     def check_all_karma_thresholds(self):
         """
         If we just pushed testing updates see if any of them now meet either of