[packman] correct syntax for building libdvdcss

[Tim Conrad]

Hi,

I noticed on your site you provide instructions for building an rpm for
libdvdcss, however in your instructions you say to use the rpm --rebuild
command. In the case of SuSE 10.1 it's rpmbuild --rebuild. And also it
might be a good idea to let users know to replace --target=i686 with
--target=x86_64 if they have 64 bit installs. Thanks for the
instructions though. Great job!