perf tests pmu: Initialize all fields of test_pmu variable

Instead of explicitely initializing just the .name and .alias_name,
use struct member named initialization of just the non-null -name field,
the compiler will initialize all the other non-explicitely initialized
fields to NULL.

This makes the code more robust, avoiding the error recently fixed when
the .alias_name was used and contained a random value.
Reviewed-by: Veronika Molnarova <vmolnaro@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Radostin Stoyanov <rstoyano@redhat.com>
Link: https://lore.kernel.org/lkml/e26941f9-f86c-4f2e-b812-20c49fb2c0d3@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/pmu.c

@@ -458,10 +458,10 @@ static int test__name_cmp(struct test_suite *test __maybe_unused, int subtest __
  */
 static int test__pmu_match(struct test_suite *test __maybe_unused, int subtest __maybe_unused)
 {
-	struct perf_pmu test_pmu;
-	test_pmu.alias_name = NULL;
+	struct perf_pmu test_pmu = {
+		.name = "pmuname",
+	};
 
-	test_pmu.name = "pmuname";
 	TEST_ASSERT_EQUAL("Exact match", perf_pmu__match(&test_pmu, "pmuname"),	     true);
 	TEST_ASSERT_EQUAL("Longer token", perf_pmu__match(&test_pmu, "longertoken"), false);
 	TEST_ASSERT_EQUAL("Shorter token", perf_pmu__match(&test_pmu, "pmu"),	     false);