staging: comedi: refactor comedi_dev_from_minor()
staging: comedi: refactor comedi_dev_from_minor()

Refactor `comedi_dev_from_minor()` to call one of two new functions
`comedi_dev_from_board_minor()` (for minor device numbers less than
`COMEDI_NUM_BOARD_MINORS`) or `comedi_dev_from_subdevice_minor()` (for
minor device numbers greater than or equal to `COMEDI_NUM_BOARD_MINORS`,
which are subdevice minor device numbers).

Remove `comedi_file_info_from_minor()` as it is no longer used.

This is a step towards removing `struct comedi_file_info`.

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>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs