net/mlx5e: Fix mlx5e_priv_init() cleanup flow

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: Fix mlx5e_priv_init() cleanup flow

When mlx5e_priv_init() fails, the cleanup flow calls mlx5e_selq_cleanup which
calls mlx5e_selq_apply() that assures that the `priv->state_lock` is held using
lockdep_is_held().

Acquire the state_lock in mlx5e_selq_cleanup().

Kernel log:
=============================
WARNING: suspicious RCU usage
6.8.0-rc3_net_next_841a9b5 #1 Not tainted
-----------------------------
drivers/net/ethernet/mellanox/mlx5/core/en/selq.c:124 suspicious rcu_dereference_protected() usage!

other info that might help us debug this:

rcu_scheduler_active = 2, debug_locks = 1
2 locks held by systemd-modules/293:
#0: ffffffffa05067b0 (devices_rwsem){++++}-{3:3}, at: ib_register_client+0x109/0x1b0 [ib_core]
#1: ffff8881096c65c0 (&device->client_data_rwsem){++++}-{3:3}, at: add_client_context+0x104/0x1c0 [ib_core]

stack backtrace:
CPU: 4 PID: 293 Comm: systemd-modules Not tainted 6.8.0-rc3_net_next_841a9b5 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x8a/0xa0
lockdep_rcu_suspicious+0x154/0x1a0
mlx5e_selq_apply+0x94/0xa0 [mlx5_core]
mlx5e_selq_cleanup+0x3a/0x60 [mlx5_core]
mlx5e_priv_init+0x2be/0x2f0 [mlx5_core]
mlx5_rdma_setup_rn+0x7c/0x1a0 [mlx5_core]
rdma_init_netdev+0x4e/0x80 [ib_core]
? mlx5_rdma_netdev_free+0x70/0x70 [mlx5_core]
ipoib_intf_init+0x64/0x550 [ib_ipoib]
ipoib_intf_alloc+0x4e/0xc0 [ib_ipoib]
ipoib_add_one+0xb0/0x360 [ib_ipoib]
add_client_context+0x112/0x1c0 [ib_core]
ib_register_client+0x166/0x1b0 [ib_core]
? 0xffffffffa0573000
ipoib_init_module+0xeb/0x1a0 [ib_ipoib]
do_one_initcall+0x61/0x250
do_init_module+0x8a/0x270
init_module_from_file+0x8b/0xd0
idempotent_init_module+0x17d/0x230
__x64_sys_finit_module+0x61/0xb0
do_syscall_64+0x71/0x140
entry_SYSCALL_64_after_hwframe+0x46/0x4e
</TASK>