net: rtlwifi: properly check for alloc_workqueue() failure

stable inclusion
from stable-5.10.40
commit e81f94a71b0070b1cdc65b619892fa53220853b8
bugzilla: 51882
CVE: NA

--------------------------------

commit 30b0e0ee upstream.

If alloc_workqueue() fails, properly catch this and propagate the error
to the calling functions, so that the devuce initialization will
properly error out.

Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: Bryan Brattlof <hello@bryanbrattlof.com>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20210503115736.2104747-14-gregkh@linuxfoundation.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chen Jun <chenjun102@huawei.com>
Acked-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>