RDMA/bng_re: Remove unnessary validity checks

RDMA/bng_re: Remove unnessary validity checks

Fix below smatch warning:
drivers/infiniband/hw/bng_re/bng_dev.c:113
bng_re_net_ring_free() warn: variable dereferenced before check 'rdev'
(see line 107)

current driver has unnessary validity checks. So, removing these
unnessary validity checks.

Fixes: 4f830cd8d7fe ("RDMA/bng_re: Add infrastructure for enabling Firmware channel")
Fixes: 745065770c2d ("RDMA/bng_re: Register and get the resources from bnge driver")
Fixes: 04e031ff6e60 ("RDMA/bng_re: Initialize the Firmware and Hardware")
Fixes: d0da769c19d0 ("RDMA/bng_re: Add Auxiliary interface")
Reported-by: Simon Horman <horms@kernel.org>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202601010413.sWadrQel-lkp@intel.com/
Signed-off-by: Siva Reddy Kallam <siva.kallam@broadcom.com>
Link: https://patch.msgid.link/20260218091246.1764808-2-siva.kallam@broadcom.com
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>