Compute loss for each path

Signed-off-by: Adrien Gallouët <adrien@gallouet.fr>

mud.h

@@ -36,6 +36,7 @@ struct mud_path {
     uint64_t window;
     uint64_t window_time;
     uint64_t window_size;
+    uint64_t loss;
     struct {
         size_t min;
         size_t max;