Fix various typos in comments and documentation. Cc: Chasel Chiu <chasel.chiu@intel.com> Cc: Nate DeSimone <nathaniel.l.desimone@intel.com> Cc: Star Zeng <star.zeng@intel.com> Reviewed-by: Philippe Mathieu-Daude <philmd@redhat.com> Signed-off-by: Philippe Mathieu-Daude <philmd@redhat.com> Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com> Reviewed-by: Chasel Chiu <chasel.chiu@intel.com> Reviewed-by: Star Zeng <star.zeng@intel.com>