brcmfmac: Fix warning message after dongle setup failed

[ Upstream commit 6aa5a83a7ed8036c1388a811eb8bdfa77b21f19c ]

Brcmfmac showed warning message in fweh.c when checking the size of event
queue which is not initialized. Therefore, we only cancel the worker and
reset event handler only when it is initialized.

[  145.505899] brcmfmac 0000:02:00.0: brcmf_pcie_setup: Dongle setup
[  145.929970] ------------[ cut here ]------------
[  145.929994] WARNING: CPU: 0 PID: 288 at drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c:312
brcmf_fweh_detach+0xbc/0xd0 [brcmfmac]
...
[  145.930029] Call Trace:
[  145.930036]  brcmf_detach+0x77/0x100 [brcmfmac]
[  145.930043]  brcmf_pcie_remove+0x79/0x130 [brcmfmac]
[  145.930046]  pci_device_remove+0x39/0xc0
[  145.930048]  device_release_driver_internal+0x141/0x200
[  145.930049]  device_release_driver+0x12/0x20
[  145.930054]  brcmf_pcie_setup+0x101/0x3c0 [brcmfmac]
[  145.930060]  brcmf_fw_request_done+0x11d/0x1f0 [brcmfmac]
[  145.930062]  ? lock_timer_base+0x7d/0xa0
[  145.930063]  ? internal_add_timer+0x1f/0xa0
[  145.930064]  ? add_timer+0x11a/0x1d0
[  145.930066]  ? __kmalloc_track_caller+0x18c/0x230
[  145.930068]  ? kstrdup_const+0x23/0x30
[  145.930069]  ? add_dr+0x46/0x80
[  145.930070]  ? devres_add+0x3f/0x50
[  145.930072]  ? usermodehelper_read_unlock+0x15/0x20
[  145.930073]  ? _request_firmware+0x288/0xa20
[  145.930075]  request_firmware_work_func+0x36/0x60
[  145.930077]  process_one_work+0x144/0x360
[  145.930078]  worker_thread+0x4d/0x3c0
[  145.930079]  kthread+0x112/0x150
[  145.930080]  ? rescuer_thread+0x340/0x340
[  145.930081]  ? kthread_park+0x60/0x60
[  145.930083]  ret_from_fork+0x25/0x30

Signed-off-by: Wright Feng <wright.feng@cypress.com>
Signed-off-by: Chi-hsien Lin <chi-hsien.lin@cypress.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20200928054922.44580-3-wright.feng@cypress.com


Signed-off-by: Sasha Levin <sashal@kernel.org>