hw/net/smc91c111: Let smc91c111_can_receive() return a boolean

The smc91c111_can_receive() function simply returns a boolean value.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>

hw/net/smc91c111.c

@@ -130,16 +130,16 @@ static void smc91c111_update(smc91c111_state *s)
     qemu_set_irq(s->irq, level);
 }
 
-static int smc91c111_can_receive(smc91c111_state *s)
+static bool smc91c111_can_receive(smc91c111_state *s)
 {
     if ((s->rcr & RCR_RXEN) == 0 || (s->rcr & RCR_SOFT_RST)) {
-        return 1;
+        return true;
     }
     if (s->allocated == (1 << NUM_PACKETS) - 1 ||
         s->rx_fifo_len == NUM_PACKETS) {
-        return 0;
+        return false;
     }
-    return 1;
+    return true;
 }
 
 static inline void smc91c111_flush_queued_packets(smc91c111_state *s)