RDMA: Fix netdev tracker in ib_device_set_netdev

RDMA: Fix netdev tracker in ib_device_set_netdev

If a netdev has already been assigned, ib_device_set_netdev needs to
release the reference on the older netdev but it is mistakenly being
called for the new netdev. Fix it and in the process use netdev_put
to be symmetrical with the netdev_hold.

Fixes: 09f530f0c6d6 ("RDMA: Add netdevice_tracker to ib_device_set_netdev()")
Signed-off-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240710203310.19317-1-dsahern@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>