s4: Patch for "libnet/libnet_samsync_ldb.c"

[Matthias Dieter Wallnöfer]

Hi Jelmer,

while thinking about the substitution of "samdb_msg_add_string" (other 
thread) I've come across on the "libnet/libnet_samsync_ldb.c" file. 
Briefly said there exist many "samdb/ldb_msg_add" calls without return 
code checks. To solve the issue I've written the following patch: 
http://repo.or.cz/w/Samba/mdw.git/commitdiff/33d56971b23e8124563827cdc0bafb1a02060d1d 
and wanted to know what you think about my macro approach. Probably it 
could be worth to move the macro to a common location.

Cheers,
Matthias