dmaengine: sh: rz-dmac: Fix lockdep assert warning

Fix the below lockdep assert warning by holding vc.lock for
vchan_get_all_descriptors().

WARNING: virt-dma.h:188 rz_dmac_terminate_all
pc : rz_dmac_terminate_all
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20240625170119.173595-1-biju.das.jz@bp.renesas.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/sh/rz-dmac.c

@@ -540,8 +540,8 @@ static int rz_dmac_terminate_all(struct dma_chan *chan)
 	spin_lock_irqsave(&channel->vc.lock, flags);
 	list_splice_tail_init(&channel->ld_active, &channel->ld_free);
 	list_splice_tail_init(&channel->ld_queue, &channel->ld_free);
-	spin_unlock_irqrestore(&channel->vc.lock, flags);
 	vchan_get_all_descriptors(&channel->vc, &head);
+	spin_unlock_irqrestore(&channel->vc.lock, flags);
 	vchan_dma_desc_free_list(&channel->vc, &head);
 
 	return 0;