mdev: add support for - "dont stop here" char

function                                             old     new   delta
make_device                                         1340    1362     +22
packed_usage                                       26291   26299      +8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 30/0)               Total: 30 bytes

diff --git a/include/usage.h b/include/usage.h
index 7111e90..d3bf784 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -2560,7 +2560,7 @@
        " echo /bin/mdev >/proc/sys/kernel/hotplug\n" \
 	USE_FEATURE_MDEV_CONF( \
        "It uses /etc/mdev.conf with lines\n" \
-       "DEVNAME UID:GID PERM" \
+       "[-]DEVNAME UID:GID PERM" \
 			USE_FEATURE_MDEV_RENAME(" [>|=PATH]") \
 			USE_FEATURE_MDEV_EXEC(" [@|$|*COMMAND]") \
 	) \