RDMA/bnxt_re: Remove always true dattr validity check

RDMA/bnxt_re: Remove always true dattr validity check

res->dattr is always valid at this point as it was initialized
during device addition in bnxt_re_add_device().

This change is fixing the following smatch error:
drivers/infiniband/hw/bnxt_re/qplib_fp.c:1090 bnxt_qplib_create_qp()
     error: we previously assumed 'res->dattr' could be null (see line 985)

Fixes: 07f830ae4913 ("RDMA/bnxt_re: Adds MSN table capability for Gen P7 adapters")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202411222329.YTrwonWi-lkp@intel.com/
Link: https://patch.msgid.link/be0d8836b64cba3e479fbcbca717acad04aae02e.1732626579.git.leonro@nvidia.com
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>