aio: remove process_queue callback and qemu_aio_process_queue

Both unused after the previous patch.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/posix-aio-compat.c b/posix-aio-compat.c
index 1066c60..68361f5 100644
--- a/posix-aio-compat.c
+++ b/posix-aio-compat.c
@@ -663,8 +663,7 @@
     fcntl(s->rfd, F_SETFL, O_NONBLOCK);
     fcntl(s->wfd, F_SETFL, O_NONBLOCK);
 
-    qemu_aio_set_fd_handler(s->rfd, posix_aio_read, NULL, posix_aio_flush,
-        NULL, s);
+    qemu_aio_set_fd_handler(s->rfd, posix_aio_read, NULL, posix_aio_flush, s);
 
     ret = pthread_attr_init(&attr);
     if (ret)