LU-6215 llite: make_request_fn returns blk_qc_t in kernel 4.4

LU-6215 llite: make_request_fn returns blk_qc_t in kernel 4.4

For the 4.4 kernel request_queue.make_request_fn is defined as
a function returns blk_qc_t. loop_make_request() should return
BLK_QC_T_NONE in this case.

Linux-commit: dece16353ef47d8d33f5302bc158072a9d65e26f

Signed-off-by: Li Dongyang <dongyang.li@anu.edu.au>
Change-Id: I20a796caf6d8e6411f084db2392683c12307a0bf
Reviewed-on: http://review.whamcloud.com/18730
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>