Fix a comment to indicate that TALLOC_FREE must be used to free an allocated array of strings.

Signed-off-by: Richard Sharpe <realrichardsharpe@gmail.com>
Reviewed-by: Volker Lendecke <vl@samba.org>

Autobuild-User(master): Volker Lendecke <vl@samba.org>
Autobuild-Date(master): Fri Dec 26 22:54:51 CET 2014 on sn-devel-104
lib: Use talloc_zero_array instead of memset

Signed-off-by: Volker Lendecke <vl@samba.org>
Reviewed-by: Martin Schwenke <martin@meltin.net>

Autobuild-User(master): Martin Schwenke <martins@samba.org>
Autobuild-Date(master): Sat Dec 27 01:27:08 CET 2014 on sn-devel-104