spice-core: fix watching for write events

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

ui/spice-core.c

diff --git a/ui/spice-core.c b/ui/spice-core.c
index 6a1cf17..45807ed 100644
--- a/ui/spice-core.c
+++ b/ui/spice-core.c
@@ -95,7 +95,7 @@
         on_read = watch_read;
     }
     if (watch->event_mask & SPICE_WATCH_EVENT_WRITE) {
-        on_read = watch_write;
+        on_write = watch_write;
     }
     qemu_set_fd_handler(watch->fd, on_read, on_write, watch);
 }