dmaengine: altera: Use IRQ-safe spinlock calls in the error paths as well

The patch edf10919 [dmaengine: altera: fix spinlock usage] missed to
change 2 occurrences of spin_unlock_bh() to spin_unlock_irqrestore().
This patch fixes this by moving to the IRQ-safe call in the error
paths as well.

Fixes: edf10919 (dmaengine: altera: fix spinlock usage)
Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Sylvain Lesne <lesne@alse-fr.com>
[add fixes tag and fix typo in log]
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/altera-msgdma.c

@@ -344,7 +344,7 @@ msgdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst,
 
 	spin_lock_irqsave(&mdev->lock, irqflags);
 	if (desc_cnt > mdev->desc_free_cnt) {
-		spin_unlock_bh(&mdev->lock);
+		spin_unlock_irqrestore(&mdev->lock, irqflags);
 		dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev);
 		return NULL;
 	}
@@ -407,7 +407,7 @@ msgdma_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
 
 	spin_lock_irqsave(&mdev->lock, irqflags);
 	if (desc_cnt > mdev->desc_free_cnt) {
-		spin_unlock_bh(&mdev->lock);
+		spin_unlock_irqrestore(&mdev->lock, irqflags);
 		dev_dbg(mdev->dev, "mdev %p descs are not available\n", mdev);
 		return NULL;
 	}