8286392: Address possibly lossy conversions in jdk.jfr

Reviewed-by: mgronlun

src/jdk.jfr/share/classes/jdk/jfr/internal/PlatformRecording.java

@@ -731,7 +731,7 @@ public final class PlatformRecording implements AutoCloseable {
                     result = reduceFromEnd(maxSize, result);
                 }
             }
-            int size = 0;
+            long size = 0;
             for (RepositoryChunk r : result) {
                 size += r.getSize();
                 r.use();