RDMA/bnxt_re: Remove a redundant check inside bnxt_re_update_gid

RDMA/bnxt_re: Remove a redundant check inside bnxt_re_update_gid

The NULL check inside bnxt_re_update_gid() always return false.  If
sgid_tbl->tbl is not allocated, then dev_init would have failed.

Fixes: 5fac5b1b297f ("RDMA/bnxt_re: Add vlan tag for untagged RoCE traffic when PFC is configured")
Link: https://lore.kernel.org/r/1684478897-12247-5-git-send-email-selvin.xavier@broadcom.com
Reviewed-by: Saravanan Vajravel <saravanan.vajravel@broadcom.com>
Reviewed-by: Damodharam Ammepalli <damodharam.ammepalli@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Signed-off-by: Selvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>