Staging: hv: fix sysfs symlink on hv block device

Staging: hv: fix sysfs symlink on hv block device

commit 268eff909afaca93188d2d14554cbf824f6a0e41 upstream.

The block device does not create the proper symlink in sysfs because we
forgot to set up the gendisk structure properly.  This patch fixes the
issue.

Signed-off-by: K. Y. Srinivasan <ksrinivasan@novell.com>
Cc: Hank Janssen <hjanssen@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>