[AX.25]: Use constant instead of magic number

Signed-off-by: Ralf Baechle DL5RB <ralf@linux-mips.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@mandriva.com>

net/rose/rose_route.c

@@ -727,7 +727,7 @@ int rose_rt_ioctl(unsigned int cmd, void __user *arg)
 		}
 		if (rose_route.mask > 10) /* Mask can't be more than 10 digits */
 			return -EINVAL;
-		if (rose_route.ndigis > 8) /* No more than 8 digipeats */
+		if (rose_route.ndigis > AX25_MAX_DIGIS)
 			return -EINVAL;
 		err = rose_add_node(&rose_route, dev);
 		dev_put(dev);