RDMA/nes: Avoid complaints about unused variables

Avoid that the compiler reports the following when building with W=1:

drivers/infiniband/hw/nes/nes_utils.c: In function 'nes_arp_table':
drivers/infiniband/hw/nes/nes_utils.c:689:9: warning: variable 'tmp_addr' set but not used [-Wunused-but-set-variable]
  __be32 tmp_addr;
         ^~~~~~~~
drivers/infiniband/hw/nes/nes_hw.c: In function 'flush_wqes':
drivers/infiniband/hw/nes/nes_hw.c:3840:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
  int ret;
      ^~~
drivers/infiniband/hw/nes/nes_verbs.c: In function 'nes_setup_virt_qp':
drivers/infiniband/hw/nes/nes_verbs.c:811:6: warning: variable 'pbl_entries' set but not used [-Wunused-but-set-variable]
  u32 pbl_entries;
      ^~~~~~~~~~~
drivers/infiniband/hw/nes/nes_verbs.c: In function 'nes_dereg_mr':
drivers/infiniband/hw/nes/nes_verbs.c:2487:6: warning: variable 'minor_code' set but not used [-Wunused-but-set-variable]
  u16 minor_code;
      ^~~~~~~~~~
drivers/infiniband/hw/nes/nes_cm.c: In function 'mini_cm_recv_pkt':
drivers/infiniband/hw/nes/nes_cm.c:2570:20: warning: variable 'tmp_saddr' set but not used [-Wunused-but-set-variable]
  __be32 tmp_daddr, tmp_saddr;
                    ^~~~~~~~~
drivers/infiniband/hw/nes/nes_cm.c:2570:9: warning: variable 'tmp_daddr' set but not used [-Wunused-but-set-variable]
  __be32 tmp_daddr, tmp_saddr;
         ^~~~~~~~~
drivers/infiniband/hw/nes/nes_cm.c: In function 'cm_event_connected':
drivers/infiniband/hw/nes/nes_cm.c:3578:22: warning: variable 'raddr' set but not used [-Wunused-but-set-variable]
  struct sockaddr_in *raddr;
                      ^~~~~
drivers/infiniband/hw/nes/nes_cm.c: In function 'cm_event_reset':
drivers/infiniband/hw/nes/nes_cm.c:3753:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
  int ret;
      ^~~

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Tatyana Nikolova <Tatyana.E.Nikolova@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>