xen: Add compatibility aliases for frontend drivers

Before getting merged, xen-blkfront was xenblk and
xen-netfront was xennet.

Temporarily adding compatibility module aliases
eases upgrades from older versions by e.g. allowing
mkinitrd to find the new version of the module.
Signed-off-by: NMark McLoughlin <markmc@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

drivers/block/xen-blkfront.c

@@ -1016,3 +1016,4 @@ MODULE_DESCRIPTION("Xen virtual block device frontend");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_BLOCKDEV_MAJOR(XENVBD_MAJOR);
 MODULE_ALIAS("xen:vbd");
+MODULE_ALIAS("xenblk");

drivers/net/xen-netfront.c

@@ -1810,3 +1810,4 @@ module_exit(netif_exit);
 MODULE_DESCRIPTION("Xen virtual network device frontend");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("xen:vif");
+MODULE_ALIAS("xennet");