Staging: hv: comment out blkdev variable in blkvsc_ioctl

This variable generated an unused variable warning due to other code
in the fuction being commented out.  This comments out the variable
defination so that the code compiles without warnings.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Cc: Hank Janssen <hjanssen@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/hv/blkvsc_drv.c

@@ -1461,7 +1461,7 @@ int blkvsc_getgeo(struct block_device *bd, struct hd_geometry *hg)
 static int blkvsc_ioctl(struct block_device *bd, fmode_t mode,
 			unsigned cmd, unsigned long argument)
 {
-	struct block_device_context *blkdev = bd->bd_disk->private_data;
+/*	struct block_device_context *blkdev = bd->bd_disk->private_data; */
 	int ret=0;
 
 	switch (cmd)