[dsymutil] Print the swift interface modification time in warning

The warning was printing the timestamp from the debug map twice rather
than both the file system modification time and debug map modification
time.

rdar://86036385

Differential revision: https://reviews.llvm.org/D117331

llvm/tools/dsymutil/DwarfLinkerForBinary.cpp

@@ -418,7 +418,7 @@ bool DwarfLinkerForBinary::link(const DebugMap &Map) {
           // Not using the helper here as we can easily stream TimePoint<>.
           WithColor::warning()
               << File << ": timestamp mismatch between swift interface file ("
-              << sys::TimePoint<>(Obj->getTimestamp()) << ") and debug map ("
+              << sys::TimePoint<>(ModificationTime) << ") and debug map ("
               << sys::TimePoint<>(Obj->getTimestamp()) << ")\n";
           continue;
         }