The rtnl lock is taken just the line above, no need to take the rcu also.

Fixes: 1788b856 ("gtp: fix use-after-free in gtp_encap_destroy()")
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>