fix pagecache category in atrace_userdebug

pagecache should be usable on userdebug but is in filemap, not
pagecache.

Test: works
bug 120744209

Change-Id: Id6a59639595dccc716d8fe137762619bec8c9363
diff --git a/cmds/atrace/atrace_userdebug.rc b/cmds/atrace/atrace_userdebug.rc
index f4e5b98..5c28c9d 100644
--- a/cmds/atrace/atrace_userdebug.rc
+++ b/cmds/atrace/atrace_userdebug.rc
@@ -9,8 +9,8 @@
     chmod 0666 /sys/kernel/debug/tracing/events/workqueue/enable
     chmod 0666 /sys/kernel/tracing/events/regulator/enable
     chmod 0666 /sys/kernel/debug/tracing/events/regulator/enable
-    chmod 0666 /sys/kernel/tracing/events/pagecache/enable
-    chmod 0666 /sys/kernel/debug/tracing/events/pagecache/enable
+    chmod 0666 /sys/kernel/tracing/events/filemap/enable
+    chmod 0666 /sys/kernel/debug/tracing/events/filemap/enable
 
     # irq
     chmod 0666 /sys/kernel/tracing/events/irq/enable