The completed transaction list is used in gsi_channel_trans_complete()
to return the next transaction in completed state.

Add some temporary checks to verify the transaction indicated by the
completed ID matches the one first in this list.

Similarly, we use the pending and completed transaction lists when
cancelling pending transactions in gsi_channel_trans_cancel_pending().

Add temporary checks there to verify the transactions indicated by
IDs match those tracked by these lists.
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>