fixup

perf/src/sigverify.rs

@@ -509,34 +509,37 @@ pub fn shrink_batches(batches: &mut Vec<PacketBatch>) -> usize {
     let mut ii = 0;
     let mut j = 1;
     let mut jj = 0;
+    let mut last = 0;
     while j < batches.len() {
         while jj < batches[j].packets.len() {
             if batches[j].packets[jj].meta.discard() {
-                jj += 1;
+                jj = jj.saturating_add(1);
                 continue;
             }
+            last = j;
             let mut done = false;
             while i < j && !done {
                 while ii < batches[i].packets.len() {
                     if batches[i].packets[ii].meta.discard() {
                         batches[i].packets[ii] = batches[j].packets[jj].clone();
                         batches[j].packets[jj].meta.set_discard(true);
+                        last = i;
                         done = true;
                         break;
                     }
                     ii += 1;
                 }
                 if ii >= batches[i].packets.len() {
                     ii = 0;
-                    i += 1;
+                    i = i.saturating_add(1);
                 }
             }
-            jj += 1;
+            jj = jj.saturating_add(1);
         }
         jj = 0;
-        j += 1;
+        j = j.saturating_add(1);
     }
-    i + 1
+    last + 1
 }
 
 pub fn ed25519_verify_cpu(batches: &mut [PacketBatch], reject_non_vote: bool, packet_count: usize) {