Move ftrace_reader code into src/traced/probes/ftrace

Reduces the API surface hiding the ftrace reader into src/.

Change-Id: Ie89b90013c6bd22ceed8aaf9595a23a4185b7b92
diff --git a/tools/test_data.txt b/tools/test_data.txt
index 36c9cdb..d2dd686 100644
--- a/tools/test_data.txt
+++ b/tools/test_data.txt
@@ -1,4 +1,4 @@
 # List of test deps that should be pushed on the device. Paths are relative
 # to the root.
-src/ftrace_reader/test/data/
+src/traced/probes/ftrace/test/data/
 src/traced/probes/filesystem/testdata/