xen-blkfront: Fix one off warning about name clash

Avoid telling users to use xvde and onwards when using xvde.
Acked-by: NStefano Stabellini <stefano.stabellini@eu.citrix.com>
Signed-off-by: NStefan Bader <stefan.bader@canonical.com>
Signed-off-by: NKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>

drivers/block/xen-blkfront.c

@@ -529,7 +529,7 @@ static int xlvbd_alloc_gendisk(blkif_sector_t capacity,
 		minor = BLKIF_MINOR_EXT(info->vdevice);
 		nr_parts = PARTS_PER_EXT_DISK;
 		offset = minor / nr_parts;
-		if (xen_hvm_domain() && offset <= EMULATED_HD_DISK_NAME_OFFSET + 4)
+		if (xen_hvm_domain() && offset < EMULATED_HD_DISK_NAME_OFFSET + 4)
 			printk(KERN_WARNING "blkfront: vdevice 0x%x might conflict with "
 					"emulated IDE disks,\n\t choose an xvd device name"
 					"from xvde on\n", info->vdevice);