staging: comedi: remove the "Allocate the subdevice..." comments

These comments are redundant. The function name 'comedi_alloc_subdevices'
provides this information.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <ian@mev.co.uk>
Cc: Frank Mori Hess <fmhess@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>