Invoking the --help option of any tool should not return with an error,
if that tool does have a documented and implemented help option.
Adjust the usage() function to exit with either error or success.
Handle the existing entry in the option table to call usage accordingly.
Adjust the getopt value for help. The char '?' is returned for unknown
options. Returning 'h' instead of '?' allows to handle --help.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Reviewed-by: George Dunlap <george.dunlap@cloud.com>
Olaf Hering
a40c3aa126