perf python scripting: Append examples to err msg about audit-libs-python

perf python scripting: Append examples to err msg about audit-libs-python

To print syscall names, the audit-libs-python package is required.. If
not installed, it prints this error string:

    # perf script syscall-counts
    Install the audit-libs-python package to get syscall names.

But the package name is different in Ubuntu, mention that in the error
message, similar to a error message of util/trace-event-scripting.c:

    # perf script syscall-counts
    Install the audit-libs-python package to get syscall names.
    For example:
      # apt-get install python-audit (Ubuntu)
      # yum install audit-libs-python (Fedora)
      etc.

Signed-off-by: Taeung Song <treeze.taeung@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: http://lkml.kernel.org/r/1455018790-13425-1-git-send-email-treeze.taeung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>