misc: fastrpc: add checked value for dma_set_mask

There be should check return value from dma_set_mask to throw some info
if fail to set dma mask.

Detected by CoverityScan, CID# 1443983:  Error handling issues (CHECKED_RETURN)

Fixes: f6f9279f ("misc: fastrpc: Add Qualcomm fastrpc basic driver model")
Signed-off-by: Bo YU <tsu.yubo@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/fastrpc.c

@@ -1184,6 +1184,7 @@ static int fastrpc_cb_probe(struct platform_device *pdev)
 	struct fastrpc_session_ctx *sess;
 	struct device *dev = &pdev->dev;
 	int i, sessions = 0;
+	int rc;
 
 	cctx = dev_get_drvdata(dev->parent);
 	if (!cctx)
@@ -1213,7 +1214,11 @@ static int fastrpc_cb_probe(struct platform_device *pdev)
 	}
 	cctx->sesscount++;
 	spin_unlock(&cctx->lock);
-	dma_set_mask(dev, DMA_BIT_MASK(32));
+	rc = dma_set_mask(dev, DMA_BIT_MASK(32));
+	if (rc) {
+		dev_err(dev, "32-bit DMA enable failed\n");
+		return rc;
+	}
 
 	return 0;
 }