perf tools: Fix error index for pmu event parser

For events we provide specific error message we need to set error column
index, PMU parser is missing that, adding it.

Before:

  $ perf stat -e cycles,krava/cycles/ kill
  event syntax error: 'cycles,krava/cycles/'
                       \___ Cannot find PMU `krava'. Missing kernel support?

After:

  $ perf stat -e cycles,krava/cycles/ kill
  event syntax error: 'cycles,krava/cycles/'
                              \___ Cannot find PMU `krava'. Missing kernel support?

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <frederic@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/20180606221513.11302-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>