bnad: fix work_queue type mismatch

clang-16 warns about a function pointer cast:

drivers/net/ethernet/brocade/bna/bnad.c:1995:4: error: cast from 'void (*)(struct delayed_work *)' to 'work_func_t' (aka 'void (*)(struct work_struct *)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
 1995 |                         (work_func_t)bnad_tx_cleanup);
drivers/net/ethernet/brocade/bna/bnad.c:2252:4: error: cast from 'void (*)(void *)' to 'work_func_t' (aka 'void (*)(struct work_struct *)') converts to incompatible function type [-Werror,-Wcast-function-type-strict]
 2252 |                         (work_func_t)(bnad_rx_cleanup));

The problem here is mixing up work_struct and delayed_work, which relies
the former being the first member of the latter.

Change the code to use consistent types here to address the warning and
make it more robust against workqueue interface changes.

Side note: the use of a delayed workqueue for cleaning up TX descriptors
is probably a bad idea since this introduces a noticeable delay. The
driver currently does not appear to use BQL, but if one wanted to add
that, this would have to be changed as well.

Fixes: 01b54b14 ("bna: tx rx cleanup fix")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>