drivers/rapidio/devices/tsi721.c: fix error return code

Convert a nonnegative error return code to a negative one, as returned
elsewhere in the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
(
if@p1 (\(ret < 0\|ret != 0\))
 { ... return ret; }
|
ret@p1 = 0
)
... when != ret = e1
    when != &ret
*if(...)
{
  ... when != ret = e2
      when forall
 return ret;
}
// </smpl>
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rapidio/devices/tsi721.c

@@ -2316,7 +2316,8 @@ static int __devinit tsi721_probe(struct pci_dev *pdev,
 
 	/* Configure DMA attributes. */
 	if (pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) {
-		if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) {
+		err = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
+		if (err) {
 			dev_info(&pdev->dev, "Unable to set DMA mask\n");
 			goto err_unmap_bars;
 		}