perf parse-events: Additional error reporting

When no events or PMUs match report an error for event_pmu:

Before:
```
$ perf stat -e 'asdfasdf' -a sleep 1
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events
```

After:
```
$ perf stat -e 'asdfasdf' -a sleep 1
event syntax error: 'asdfasdf'
                     \___ Bad event name

Unabled to find PMU or event on a PMU of 'asdfasdf'
Run 'perf list' for a list of valid events

 Usage: perf stat [<options>] [<command>]

    -e, --event <event>   event selector. use 'perf list' to list available events
```

Fixes the inadvertent removal when hybrid parsing was modified.

Fixes: 70c90e4a ("perf parse-events: Avoid scanning PMUs before parsing")
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230627181030.95608-11-irogers@google.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>