[ATM]: [ambassador] Change the return type to reflect reality

Signed-off-by: NJeff Garzik <jeff@garzik.org>
Signed-off-by: NChas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/atm/ambassador.c

@@ -915,8 +915,8 @@ static irqreturn_t interrupt_handler(int irq, void *dev_id,
 
 /********** make rate (not quite as much fun as Horizon) **********/
 
-static unsigned int make_rate (unsigned int rate, rounding r,
-			       u16 * bits, unsigned int * actual) {
+static int make_rate (unsigned int rate, rounding r,
+		      u16 * bits, unsigned int * actual) {
   unsigned char exp = -1; // hush gcc
   unsigned int man = -1;  // hush gcc