isdn: hfcpci_softirq: get func return to suppress compiler warning

commit d6d6d1bc44362112e10a48d434e5b3c716152003 upstream.

Signed-off-by: Antonio Alecrim Jr <antonio.alecrim@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>