Clients may submit a new requests from the completion callback
context. The driver was not prepared to receive a request in this
state because it already held the request queue lock and a recursive
lock error is triggered.

Now all completions are queued up until we are ready to drop the queue
lock and then delivered.

The fault was triggered by TCP over an IPsec connection in the LTP
test suite:
  LTP: starting tcp4_ipsec02 (tcp_ipsec.sh -p ah -m transport -s "100 1000 65535")
  BUG: spinlock recursion on CPU#1, genload/943
   lock: 0xbf3c3094, .magic: dead4ead, .owner: genload/943, .owner_cpu: 1
  CPU: 1 PID: 943 Comm: genload Tainted: G           O    4.9.62-axis5-devel #6
  Hardware name: Axis ARTPEC-6 Platform
   (unwind_backtrace) from [<8010d134>] (show_stack+0x18/0x1c)
   (show_stack) from [<803a289c>] (dump_stack+0x84/0x98)
   (dump_stack) from [<8016e164>] (do_raw_spin_lock+0x124/0x128)
   (do_raw_spin_lock) from [<804de1a4>] (artpec6_crypto_submit+0x2c/0xa0)
   (artpec6_crypto_submit) from [<804def38>] (artpec6_crypto_prepare_submit_hash+0xd0/0x54c)
   (artpec6_crypto_prepare_submit_hash) from [<7f3165f0>] (ah_output+0x2a4/0x3dc [ah4])
   (ah_output [ah4]) from [<805df9bc>] (xfrm_output_resume+0x178/0x4a4)
   (xfrm_output_resume) from [<805d283c>] (xfrm4_output+0xac/0xbc)
   (xfrm4_output) from [<80587928>] (ip_queue_xmit+0x140/0x3b4)
   (ip_queue_xmit) from [<805a13b4>] (tcp_transmit_skb+0x4c4/0x95c)
   (tcp_transmit_skb) from [<8059f218>] (tcp_rcv_state_process+0xdf4/0xdfc)
   (tcp_rcv_state_process) from [<805a7530>] (tcp_v4_do_rcv+0x64/0x1ac)
   (tcp_v4_do_rcv) from [<805a9724>] (tcp_v4_rcv+0xa34/0xb74)
   (tcp_v4_rcv) from [<80581d34>] (ip_local_deliver_finish+0x78/0x2b0)
   (ip_local_deliver_finish) from [<8058259c>] (ip_local_deliver+0xe4/0x104)
   (ip_local_deliver) from [<805d23ec>] (xfrm4_transport_finish+0xf4/0x144)
   (xfrm4_transport_finish) from [<805df564>] (xfrm_input+0x4f4/0x74c)
   (xfrm_input) from [<804de420>] (artpec6_crypto_task+0x208/0x38c)
   (artpec6_crypto_task) from [<801271b0>] (tasklet_action+0x60/0xec)
   (tasklet_action) from [<801266d4>] (__do_softirq+0xcc/0x3a4)
   (__do_softirq) from [<80126d20>] (irq_exit+0xf4/0x15c)
   (irq_exit) from [<801741e8>] (__handle_domain_irq+0x68/0xbc)
   (__handle_domain_irq) from [<801014f0>] (gic_handle_irq+0x50/0x94)
   (gic_handle_irq) from [<80657370>] (__irq_usr+0x50/0x80)
Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>