Fix up clang 3.0 .. 3.3 triple stuff more
OpenSSL: Use linux-x86_64 not linux-generic32

As per Viktor Dukhovni's comment on:

http://openssl.6102.n7.nabble.com/compile-openssl-1-0-1e-failed-on-Ubuntu-12-10-x64-td44699.html

'The "linux-generic64" target appears to be an incomplete template for
actual 64-bit CPUs:'

.. fix found by Georg Koppen from the Tor project, thanks!