staging: comedi: comedi_test: rename waveform members
Rename the members `struct waveform_private` associated with fake
waveform generation. The affected members are `uvolt_amplitude` -->
`wf_amplitude` (the amplitude of the waveform), `usec_period` -->
`wf_period` (the period of the waveform), and `usec_current` -->
`wf_current` (the current time within a waveform period).
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>