parse-options: do not infer PARSE_OPT_NOARG from option type

parse-options: do not infer PARSE_OPT_NOARG from option type

Simplify the "takes no value" error path by relying on PARSE_OPT_NOARG
being set correctly.  That is:

 - if the PARSE_OPT_NOARG flag is set, reject --opt=value
   regardless of the option type;
 - if the PARSE_OPT_NOARG flag is unset, accept --opt=value
   regardless of the option type.

This way, the accepted usage more closely matches the usage advertised
with --help-all.

No functional change intended, since the NOARG flag is only used
with "boolean-only" option types in existing parse_options callers.

Signed-off-by: Stephen Boyd <bebarino@gmail.com>
Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>