Only write in MemTraceLogger when TL fire

Without this we log extraneous lines that were valid but not transacted with the
downstream as it was not ready, which affects validity of memtrace testing.

src/main/scala/tilelink/Coalescing.scala

@@ -1334,7 +1334,9 @@ class MemTraceLogger(
 
         // requests on TL A channel
         //
-        req.valid := tlIn.a.valid
+        // Only log trace when fired, e.g. both upstream and downstream is ready
+        // and transaction happened.
+        req.valid := tlIn.a.fire
         req.size := tlIn.a.bits.size
         req.is_store := TLUtils.AOpcodeIsStore(tlIn.a.bits.opcode)
         req.source := tlIn.a.bits.source
@@ -1378,7 +1380,9 @@ class MemTraceLogger(
 
         // responses on TL D channel
         //
-        resp.valid := tlOut.d.valid
+        // Only log trace when fired, e.g. both upstream and downstream is ready
+        // and transaction happened.
+        resp.valid := tlOut.d.fire
         resp.size := tlOut.d.bits.size
         resp.is_store := TLUtils.DOpcodeIsStore(tlOut.d.bits.opcode)
         resp.source := tlOut.d.bits.source
@@ -1412,7 +1416,7 @@ class MemTraceLogger(
     //
     // This is a clunky workaround of the fact that Chisel doesn't allow partial
     // assignment to a bitfield range of a wide signal.
-    def flattenTrace(traceLogIO: Bundle with HasTraceLine, perLane: Vec[TraceLine]) = {
+    def flattenTrace(simIO: Bundle with HasTraceLine, perLane: Vec[TraceLine]) = {
       // these will get optimized out
       val vecValid = Wire(Vec(numLanes, chiselTypeOf(perLane(0).valid)))
       val vecSource = Wire(Vec(numLanes, chiselTypeOf(perLane(0).source)))
@@ -1428,12 +1432,12 @@ class MemTraceLogger(
         vecSize(i) := l.size
         vecData(i) := l.data
       }
-      traceLogIO.valid := vecValid.asUInt
+      simIO.valid := vecValid.asUInt
-      traceLogIO.source := vecSource.asUInt
+      simIO.source := vecSource.asUInt
-      traceLogIO.address := vecAddress.asUInt
+      simIO.address := vecAddress.asUInt
-      traceLogIO.is_store := vecIsStore.asUInt
+      simIO.is_store := vecIsStore.asUInt
-      traceLogIO.size := vecSize.asUInt
+      simIO.size := vecSize.asUInt
-      traceLogIO.data := vecData.asUInt
+      simIO.data := vecData.asUInt
     }
 
     if (simReq.isDefined) {