staging: comedi: comedi_buf: remove comedi_buf_write_alloc_strict

This function is only called by comedi_buf_put(). Remove it and just
call __comedi_buf_write_alloc() directly with the strict flag set.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>