Fix leak of FILE* in dumping

Avoid fdopen as fclose, which frees the FILE*, will close
the FD which we don't want. Just normalize on dprintf instead,
and we can add buffering if it turns out to matter at some point

Test: ran 'dumpsys gfxinfo framestats' in a loop while observing PSS
Change-Id: I7808753641aa1055cfdf570c3e017017f11f1dee
diff --git a/libs/hwui/JankTracker.cpp b/libs/hwui/JankTracker.cpp
index 5b67693..afdd339 100644
--- a/libs/hwui/JankTracker.cpp
+++ b/libs/hwui/JankTracker.cpp
@@ -174,24 +174,22 @@
 }
 
 void JankTracker::dumpFrames(int fd) {
-    FILE* file = fdopen(fd, "a");
-    fprintf(file, "\n\n---PROFILEDATA---\n");
+    dprintf(fd, "\n\n---PROFILEDATA---\n");
     for (size_t i = 0; i < static_cast<size_t>(FrameInfoIndex::NumIndexes); i++) {
-        fprintf(file, "%s", FrameInfoNames[i].c_str());
-        fprintf(file, ",");
+        dprintf(fd, "%s", FrameInfoNames[i].c_str());
+        dprintf(fd, ",");
     }
     for (size_t i = 0; i < mFrames.size(); i++) {
         FrameInfo& frame = mFrames[i];
         if (frame[FrameInfoIndex::SyncStart] == 0) {
             continue;
         }
-        fprintf(file, "\n");
+        dprintf(fd, "\n");
         for (int i = 0; i < static_cast<int>(FrameInfoIndex::NumIndexes); i++) {
-            fprintf(file, "%" PRId64 ",", frame[i]);
+            dprintf(fd, "%" PRId64 ",", frame[i]);
         }
     }
-    fprintf(file, "\n---PROFILEDATA---\n\n");
-    fflush(file);
+    dprintf(fd, "\n---PROFILEDATA---\n\n");
 }
 
 void JankTracker::reset() {