staging: comedi: das08: rename the gainlist variables
staging: comedi: das08: rename the gainlist variables

`das08_pgh_gainlist[]`, `das08_pgl_gainlist[]`, and
`das08_pgm_gainlist[]` hold the gain codes indexed by range index for
various boards that support programmable gain. `das08_gainlist[]` is a
look-up table to find the appropriate gain list for a board.  These are
all associated with the analog input Comedi subdevice.  Rename the
variables to reflect that.

Signed-off-by: Ian Abbott <9e6ba6483b6a3e14d61f7c987e72ecb5b46122d6@mev.co.uk>
Reviewed-by: H Hartley Sweeten <382ff55d8e07d1082d179e669636cd1552da4f36@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs