net: bcmasp: Handle RX buffer allocation failure

net: bcmasp: Handle RX buffer allocation failure

The buffer_pg variable needs to hold an order-5 allocation (32 x
PAGE_SIZE) which, under memory pressure may fail to be allocated. Deal
with that error condition properly to avoid doing a NULL pointer
de-reference in the subsequent call to dma_map_page().

In addition, the err_reclaim_tx error label in bcmasp_netif_init() needs
to ensure that the TX NAPI object is properly deleted, otherwise
unregister_netdev() will spin forever attempting to test and clear
the NAPI_STATE_HASHED bit.

Fixes: 490cb412007d ("net: bcmasp: Add support for ASP2.0 Ethernet controller")
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Justin Chen <justin.chen@broadcom.com>
Link: https://lore.kernel.org/r/20240213173339.3438713-1-florian.fainelli@broadcom.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>