perf tools: Re-implement debug print function for linking python/perf.so

perf tools: Re-implement debug print function for linking python/perf.so

The python/perf.so python binding links a subset of objects.

Re-implement 'verbose' and 'eprintf' so they (and consequently
'pr_debug') can be used in objects linked into pythin/perf.so.

Note 'eprintf' must be re-implemented because the full version links the
browser ui.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1376484517-5339-2-git-send-email-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>