RDMA/bnxt: Delete 'nq_ptr' variable which is not used

The variable "nq_ptr" is set but never used, this generates the following
warning while compiling kernel with W=1 option.

drivers/infiniband/hw/bnxt_re/qplib_fp.c: In function 'bnxt_qplib_service_nq':
drivers/infiniband/hw/bnxt_re/qplib_fp.c:303:25: warning:
   variable 'nq_ptr' set but not used [-Wunused-but-set-variable]
303 |  struct nq_base *nqe, **nq_ptr;
    |

Fixes: fddcbbb0 ("RDMA/bnxt_re: Simplify obtaining queue entry from hw ring")
Link: https://lore.kernel.org/r/20200419132046.123887-1-leon@kernel.org


Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>