Add 'rd' alias to new brd ramdisk driver

Alias brd to rd in the hope of helping legacy users. Suggested by Jan.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/block/brd.c

@@ -397,6 +397,7 @@ module_param(max_part, int, 0);
 MODULE_PARM_DESC(max_part, "Maximum number of partitions per RAM disk");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR);
+MODULE_ALIAS("rd");
 
 #ifndef MODULE
 /* Legacy boot options - nonmodular */