[PV-on-HVM] blkfront: use %Lu instead of %llu to xenbus_gather.

The 'll' length modifier is not available with scanf (and therefore
xenbus_gather) on older kernel versions so use 'L' which is available at
least back to 2.6.5.

Signed-off-by: Ian Campbell <ian.campbell@xensource.com>

linux-2.6-xen-sparse/drivers/xen/blkfront/blkfront.c

@@ -306,7 +306,7 @@ static void connect(struct blkfront_info *info)
 	DPRINTK("blkfront.c:connect:%s.\n", info->xbdev->otherend);
 
 	err = xenbus_gather(XBT_NIL, info->xbdev->otherend,
-			    "sectors", "%llu", &sectors,
+			    "sectors", "%Lu", &sectors,
 			    "info", "%u", &binfo,
 			    "sector-size", "%lu", &sector_size,
 			    NULL);