fjes: Handle workqueue allocation failure

In the highly unlikely event that we fail to allocate either of the
"/txrx" or "/control" workqueues, we should bail cleanly rather than
blindly march on with NULL queue pointer(s) installed in the
'fjes_adapter' instance.

Cc: "David S. Miller" <davem@davemloft.net>
Reported-by: Nicolas Waisman <nico@semmle.com>
Link: https://lore.kernel.org/lkml/CADJ_3a8WFrs5NouXNqS5WYe7rebFP+_A5CheeqAyD_p7DFJJcg@mail.gmail.com/
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>