isdn: hfcpci: check the return value of dma_set_mask() in setup_hw()

The function dma_set_mask() in setup_hw() can fail, so its return value
should be checked.

Fixes: 1700fe1a ("Add mISDN HFC PCI driver")
Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/isdn/hardware/mISDN/hfcpci.c

@@ -2005,7 +2005,11 @@ setup_hw(struct hfc_pci *hc)
 	}
 	/* Allocate memory for FIFOS */
 	/* the memory needs to be on a 32k boundary within the first 4G */
-	dma_set_mask(&hc->pdev->dev, 0xFFFF8000);
+	if (dma_set_mask(&hc->pdev->dev, 0xFFFF8000)) {
+		printk(KERN_WARNING
+		       "HFC-PCI: No usable DMA configuration!\n");
+		return -EIO;
+	}
 	buffer = dma_alloc_coherent(&hc->pdev->dev, 0x8000, &hc->hw.dmahandle,
 				    GFP_KERNEL);
 	/* We silently assume the address is okay if nonzero */