perf scripts python: exported-sql-viewer.py: Fall back to /usr/local/lib/libxed.so

Fall back to /usr/local/lib/libxed.so to cater for distributions that do
not have /usr/local/lib in the library path by default.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20181104151238.15947-2-adrian.hunter@intel.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>