staging: dgnc: off by one in dgnc_mgmt_ioctl()

"dgnc_NumBoards" is the number of initialized elements in the
dgnc_Board[] array so the comparison should be ">=" instead of ">" so we
don't read invalid data.  We can remove the special handling of the
empty array now that we've fixed this bug.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dgnc/dgnc_mgmt.c

@@ -153,8 +153,7 @@ long dgnc_mgmt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 		if (copy_from_user(&brd, uarg, sizeof(int)))
 			return -EFAULT;
 
-		if ((brd < 0) || (brd > dgnc_NumBoards) ||
-		    (dgnc_NumBoards == 0))
+		if (brd < 0 || brd >= dgnc_NumBoards)
 			return -ENODEV;
 
 		memset(&di, 0, sizeof(di));