ndsend: cosmetic fixes

1. Add usage()
2. Check for number of args (fix SEGFAULT when called with less than two args)
3. Fix some error messages for clarity

Fixes part of bug #1850 (segfault and usage)

http://bugzilla.openvz.org/1850
http://bugs.debian.org/622682

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
1 file changed