colo-compare: fix the dangerous assignment

Cc: Peter Maydell <peter.maydell@linaro.org>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Zhang Chen <zhangckid@gmail.com>
Cc: Li Zhijian <lizhijian@cn.fujitsu.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Fixes: 8ec1440202
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Reported-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Mao Zhongyi <maozy.fnst@cn.fujitsu.com>
Reviewed-by: Darren Kenny <darren.kenny@oracle.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>

net/colo-compare.c

@@ -179,7 +179,7 @@ static int packet_enqueue(CompareState *s, int mode, Connection **con)
                          "drop packet");
         }
     }
-    con = &conn;
+    *con = conn;
 
     return 0;
 }