bgmac: fix requests for extra polling calls from NAPI

bgmac: fix requests for extra polling calls from NAPI

After d75b1ade567f ("net: less interrupt masking in NAPI") polling
function has to return whole budget when it wants NAPI to call it again.

Signed-off-by: Rafał Miłecki <[email protected]>
Cc: Felix Fietkau <[email protected]>
Fixes: eb64e2923a886 ("bgmac: leave interrupts disabled as long as there is work to do")
Acked-by: Felix Fietkau <[email protected]>
Signed-off-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>