LU-6215 o2iblnd: ib_alloc_fast_reg_mr() removed in 4.3

ib_alloc_fast_reg_mr() is replaced by a more generic
ib_alloc_mr() since kernel 4.3

Linux-commit: d9f272c523db47a56a64942eb6f25361c400de66

Signed-off-by: Li Dongyang <dongyang.li@anu.edu.au>
Change-Id: I53f4e7c395c83d731aaa342f308f878b07b54d61
Reviewed-on: http://review.whamcloud.com/19185
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>