For the case, that we have to capture with a default format, i.e., when the
user doesn't call S_FMT, we have to use the field value according to the
default, configured at open() time.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>