perf ordered_samples: Remove references to perf_{evlist,tool} and machines

As these can be obtained from the ordered_events pointer, via
container_of, reducing the cross section of ordered_samples.

These were added to ordered_samples in:

 commit b7b61cbebd
 Author: Arnaldo Carvalho de Melo <acme@redhat.com>
 Date:   Tue Mar 3 11:58:45 2015 -0300

    perf ordered_events: Shorten function signatures

    By keeping pointers to machines, evlist and tool in ordered_events.

But that was more a transitional patch while moving stuff out from
perf_session.c to ordered_events.c and possibly not even needed by then,
as we could use the container_of() method and instead of having the
nr_unordered_samples stats in events_stats, we can have it in
ordered_samples.

Based-on-a-patch-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Don Zickus <dzickus@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-4lk0t9js82g0tfc0x1onpkjt@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/session.h

@@ -26,6 +26,7 @@ struct perf_session {
 	u64			one_mmap_offset;
 	struct ordered_events	ordered_events;
 	struct perf_data_file	*file;
+	struct perf_tool	*tool;
 };
 
 #define PRINT_IP_OPT_IP		(1<<0)