perf tools: Remove misplaced __maybe_unused

All over the tree.

Cc: David Ahern <dsahern@gmail.com>
cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/n/tip-8nzhnokxyp8y4v7gf0j00oyb@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/data-convert-bt.c

@@ -632,7 +632,7 @@ static bool is_flush_needed(struct ctf_stream *cs)
 }
 
 static int process_sample_event(struct perf_tool *tool,
-				union perf_event *_event __maybe_unused,
+				union perf_event *_event,
 				struct perf_sample *sample,
 				struct perf_evsel *evsel,
 				struct machine *machine __maybe_unused)