rbd: Fix leaks in rbd_start_aio() error path

Signed-off-by: NKevin Wolf <kwolf@redhat.com>
Reviewed-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

block/rbd.c

@@ -685,13 +685,16 @@ static BlockDriverAIOCB *rbd_start_aio(BlockDriverState *bs,
     }
 
     if (r < 0) {
-        goto failed;
+        goto failed_completion;
     }
 
     return &acb->common;
 
+failed_completion:
+    rbd_aio_release(c);
 failed:
     g_free(rcb);
+    qemu_vfree(acb->bounce);
     qemu_aio_release(acb);
     return NULL;
 }