perf tests: Forward the perf_sample in the dwarf unwind test

perf tests: Forward the perf_sample in the dwarf unwind test

It _will_ be used, no sense in receiving it and nor fowarding it along.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-ht8v5et209wuoh5o6nh9pzyq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>