perf tools: Fix perf-read-vdsox32 not building and lib64 install dir

perf tools: Fix perf-read-vdsox32 not building and lib64 install dir

Commit:

  c6e5e9fbc3ea ("perf tools: Fix building error in x86_64 when dwarf unwind is on")

removed the definition of IS_X86_64 but not all places using it, with
the consequence that perf-read-vdsox32 would not be built anymore, and
the default lib install directory was 'lib' instead of 'lib64'.

Also needs to go to v3.19.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org # 3.19
Link: http://lkml.kernel.org/r/CAMe9rOqpGVq3D88w+D15ef7sv6G6k57ZeTvxBm46=WFgzo9p1w@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>