perf tests c2c: Report skip when the workload fails

The workload path leaves err at 0 and returns, so the test exits 0 and is
reported as a pass even though nothing was recorded and neither report
invocation ran. The check_c2c_support() path above it already sets err=2.

Set err=2 there as well so a failing workload is reported as a skip.

Fixes: ac881007c4 ("perf tests c2c: Add a basic c2c")
Reviewed-by: Tianyou Li <tianyou.li@intel.com>
Reviewed-by: Wangyang Guo <wangyang.guo@intel.com>
Signed-off-by: Jiebin Sun <jiebin.sun@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Dapeng Mi <dapeng1.mi@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@linaro.org>
Cc: Thomas Falcon <thomas.falcon@intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/c2c.sh

@@ -39,6 +39,7 @@ test_c2c_record_report() {
 	# Run a workload that does some memory operations.
 	if ! perf c2c record -o "${perfdata}" -- perf test -w datasym 1 > /dev/null 2>&1 ; then
 		echo "c2c record and report test [Skipped: perf c2c record failed during workload]"
+		err=2
 		return
 	fi