net: bcmasp: Utilize napi_complete_done() return value

Make use of the return value from napi_complete_done(). This allows
users to use the gro_flush_timeout and napi_defer_hard_irqs sysfs
attributes for configuring software interrupt coalescing.

Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Justin Chen <justin.chen@broadcom.com>
Reviewed-by: Joe Damato <joe@dama.to>
Link: https://patch.msgid.link/20250611212730.252342-2-florian.fainelli@broadcom.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>