spi: spi: Fix queue hang if previous transfer failed

The queue worker always needs to be kicked one final time after a transfer
is done in order to transition to idle (ctlr->busy = false).

Commit 69fa9590 ("spi: Ensure the io_mutex is held until
spi_finalize_current_message()") moved this code into
__spi_pump_messages(), but it was executed only if the transfer was
successful. This condition check causes ctlr-busy to stay true in case of
a failed transfer.
This in turn causes that no new work is ever scheduled to the work queue.

Fixes: 69fa9590 ("spi: Ensure the io_mutex is held until spi_finalize_current_message()")
Reported-by: NVincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: NDavid Jander <david@protonic.nl>
Link: https://lore.kernel.org/r/20220901123630.1098433-1-david@protonic.nlSigned-off-by: NMark Brown <broonie@kernel.org>

drivers/spi/spi.c

@@ -1727,8 +1727,7 @@ static void __spi_pump_messages(struct spi_controller *ctlr, bool in_kthread)
 	spin_unlock_irqrestore(&ctlr->queue_lock, flags);
 
 	ret = __spi_pump_transfer_message(ctlr, msg, was_busy);
-	if (!ret)
-		kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
+	kthread_queue_work(ctlr->kworker, &ctlr->pump_messages);
 
 	ctlr->cur_msg = NULL;
 	ctlr->fallback = false;