sparc: use scnprintf() in show_pciobppath_attr() in vio.c

snprintf() returns the number of bytes that would be written,
which may be greater than the the actual length to be written.

show_pciobppath_attr() should return the number of bytes printed
into the buffer. This is the return value of scnprintf().
Signed-off-by: Chen Zhou <chenzhou10@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

arch/sparc/kernel/vio.c

@@ -193,7 +193,7 @@ show_pciobppath_attr(struct device *dev, struct device_attribute *attr,
 	vdev = to_vio_dev(dev);
 	dp = vdev->dp;
 
-	return snprintf (buf, PAGE_SIZE, "%pOF\n", dp);
+	return scnprintf(buf, PAGE_SIZE, "%pOF\n", dp);
 }
 
 static DEVICE_ATTR(obppath, S_IRUSR | S_IRGRP | S_IROTH,