bonding: add missed __rcu annotation for curr_active_slave

bonding: add missed __rcu annotation for curr_active_slave

[ Upstream commit 3d0b738fc5adf9f380702ac1424672e4b32c3781 ]

There is one direct accesses to bond->curr_active_slave in
bond_miimon_commit(). Protected it by rcu_access_pointer()
since the later of this function also use this one.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: e95cc44763a4 ("bonding: do failover when high prio link up")
Signed-off-by: Sasha Levin <sashal@kernel.org>