perf stat: Honor event config name on --no-merge

perf stat: Honor event config name on --no-merge

If user gave an event name explicitly, it should be displayed in the
output as is.  But with --no-merge option it adds a pmu name at the
end so might confuse users.

Actually this is true for hybrid pmus, I think we should do the same
for others.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20210602212241.2175005-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>