ide: simplify async_cmd_done callbacks

Drop the unused return value.
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>
Signed-off-by: NJohn Snow <jsnow@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

hw/ide/ahci.c

@@ -1116,7 +1116,7 @@ static int ahci_dma_add_status(IDEDMA *dma, int status)
     return 0;
 }
 
-static int ahci_async_cmd_done(IDEDMA *dma)
+static void ahci_async_cmd_done(IDEDMA *dma)
 {
     AHCIDevice *ad = DO_UPCAST(AHCIDevice, dma, dma);
 
@@ -1130,8 +1130,6 @@ static int ahci_async_cmd_done(IDEDMA *dma)
         ad->check_bh = qemu_bh_new(ahci_check_cmd_bh, ad);
         qemu_bh_schedule(ad->check_bh);
     }
-
-    return 0;
 }
 
 static void ahci_irq_set(void *opaque, int n, int level)

hw/ide/internal.h

@@ -434,7 +434,7 @@ struct IDEDMAOps {
     DMAIntFunc *set_unit;
     DMAIntFunc *add_status;
     DMAVoidFunc *set_inactive;
-    DMAFunc *async_cmd_done;
+    DMAVoidFunc *async_cmd_done;
     DMARestartFunc *restart_cb;
     DMAVoidFunc *reset;
 };