An exit path in the dns_dispatch_add() function fails to get out of
the RCU critical section when returning early. Add the missing
rcu_read_unlock() call.
(cherry picked from commit 4123d59fbc)
An exit path in the dns_dispatch_add() function fails to get out of
the RCU critical section when returning early. Add the missing
rcu_read_unlock() call.
(cherry picked from commit 4123d59fbc)