mtip32xx: Remove redundant 'flush_workqueue()' calls

'destroy_workqueue()' already drains the queue before destroying it, so
there is no need to flush it explicitly.

Remove the redundant 'flush_workqueue()' calls.

This was generated with coccinelle:

@@
expression E;
@@
- 	flush_workqueue(E);
	destroy_workqueue(E);

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/0fea349c808c6cfbf549b0e33701320c7860c8b7.1634234221.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/mtip32xx/mtip32xx.c

@@ -4063,7 +4063,6 @@ static int mtip_pci_probe(struct pci_dev *pdev,
 
 msi_initialize_err:
 	if (dd->isr_workq) {
-		flush_workqueue(dd->isr_workq);
 		destroy_workqueue(dd->isr_workq);
 		drop_cpu(dd->work[0].cpu_binding);
 		drop_cpu(dd->work[1].cpu_binding);
@@ -4121,7 +4120,6 @@ static void mtip_pci_remove(struct pci_dev *pdev)
 	mtip_block_remove(dd);
 
 	if (dd->isr_workq) {
-		flush_workqueue(dd->isr_workq);
 		destroy_workqueue(dd->isr_workq);
 		drop_cpu(dd->work[0].cpu_binding);
 		drop_cpu(dd->work[1].cpu_binding);