mq: use .invalidate to cancel dirty mq state when cancelling transaction

Before the code optimistically relied on savedirty not being called a cancelled
transaction. If it was called it could save incorrect data.

Instead we now start using the invalidate method introduced in b169ba60eebe.

hgext/mq.py

@@ -654,6 +654,7 b' class queue(object):'
                 finally:
                     repo.invalidate()
                     repo.dirstate.invalidate()
+                    self.invalidate()
                 raise
         finally:
             release(tr, lock, wlock)