LU-2800 autoconf: remove LC_BLKDEV_PUT_2ARGS test

LU-2800 autoconf: remove LC_BLKDEV_PUT_2ARGS test

blkdev_put has taken two arguments since v2.6.28.
We can remove the test and dead code.

Change-Id: Ib0379f87f57ed6148750920d853604c0b2943278
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: James Simmons <uja.ornl@gmail.com>
Reviewed-on: http://review.whamcloud.com/5390
Reviewed-by: Bob Glossman <bob.glossman@intel.com>
Reviewed-by: Minh Diep <minh.diep@intel.com>
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>