RDMA/bnxt_re: Remove unpaired rtnl unlock in bnxt_re_dev_init()

The fixed commit removes all rtnl_lock() and rtnl_unlock() calls in
function bnxt_re_dev_init(), but forgets to remove a rtnl_unlock() in the
error handling path of bnxt_re_register_netdev(), which may cause a
deadlock. This bug is suggested by a static analysis tool.

Fixes: c2b777a9

 ("RDMA/bnxt_re: Refactor device add/remove functionalities")
Link: https://lore.kernel.org/r/20210816085531.12167-1-dinghao.liu@zju.edu.cn
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Acked-by: Selvin Xavier <selvin.xavier@broadcom.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>