staging: comedi: comedi_fc: use comedi_inc_scan_progress()

Since `cfc_inc_scan_progress()` is just an inline function that calls
`comedi_inc_scan_progress()`, replace calls to the former to the latter
in the "comedi_fc" module.  This is part of the migration of
functionality from the "comedi_fc" module to the core "comedi" module.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>