Staging: comedi: Remove vect_bits_t, warning_bits_t, and error_bits_t typedefs

These are enums that are not used anywhere at this time.
This removes the typedef, but leaves the enum in place.

Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>