perf tools: Fail on using multiple bits long terms without value

Currently we allow not to specify value for numeric terms and we set
them to value 1. This was originaly meant just for single bit terms to
allow user to type:

  $ perf record -e 'cpu/cpu-cycles,any'

instead of:

  $ perf record -e 'cpu/cpu-cycles,any=1'

However it works also for multi bits terms like:

  $ perf record -e 'cpu/event/' ls
  ...
  $ perf evlist -v
  ..., config: 0x1, ...

After discussion with Peter we decided making such term usage to fail,
like:

  $ perf record -e 'cpu/event/' ls
  event syntax error: 'cpu/event/'
                       \___ no value assigned for term
  ...

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1487340058-10496-4-git-send-email-jolsa@kernel.org


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