perf tests attr: Fix stat sample_type setup

>From following commit:

  commit 4979d0c7 ("perf stat record: Add record command")

we started to assign PERF_SAMPLE_IDENTIFIER to sample_type.

Fixing the attr stat tests accordingly.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Richter <tmricht@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20170703145030.12903-14-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/attr/base-stat

@@ -8,7 +8,7 @@ type=0
 size=112
 config=0
 sample_period=0
-sample_type=0
+sample_type=65536
 read_format=3
 disabled=1
 inherit=1