RDMA/bnxt_re: Fix a possible memory leak in the driver

RDMA/bnxt_re: Fix a possible memory leak in the driver

The GID context reuse logic requires the context memory to be
not freed if and when DEL_GID firmware command fails. But, if
there's no subsequent ADD_GID to reuse it, the context memory
must be freed when the driver is unloaded. Otherwise it leads
to a memory leak.

Below is the kmemleak trace reported:

unreferenced object 0xffff88817a4f34d0 (size 8):
  comm "insmod", pid 1072504, jiffies 4402561550
  hex dump (first 8 bytes):
  01 00 00 00 00 00 00 00                          ........
  backtrace (crc ccaa009e):
  __kmalloc_cache_noprof+0x33e/0x400
  0xffffffffc2db9d48
  add_modify_gid+0x5e0/0xb60 [ib_core]
  __ib_cache_gid_add+0x213/0x350 [ib_core]
  update_gid+0xf2/0x180 [ib_core]
  enum_netdev_ipv4_ips+0x3f3/0x690 [ib_core]
  enum_all_gids_of_dev_cb+0x125/0x1b0 [ib_core]
  ib_enum_roce_netdev+0x14b/0x250 [ib_core]
  ib_cache_setup_one+0x2e5/0x540 [ib_core]
  ib_register_device+0x82c/0xf10 [ib_core]
  0xffffffffc2df5ad9
  0xffffffffc2da8b07
  0xffffffffc2db174d
  auxiliary_bus_probe+0xa5/0x120
  really_probe+0x1e4/0x850
  __driver_probe_device+0x18f/0x3d0

Fixes: 4a62c5e9e2e1 ("RDMA/bnxt_re: Do not free the ctx_tbl entry if delete GID fails")
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20250805101000.233310-4-kalesh-anakkur.purayil@broadcom.com
Reviewed-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>