Statsd testdrive: remove debug line.

Oops, left the old output in the submitted CL that changed to a new
output approach.

Bug: 149914234
Test: atest --host frameworks/base/cmds/statsd/tools/localtools/test/com/android/statsd/shelltools/testdrive/*.java
Test: statsd_testdrive 90 > /tmp/testdrive
Change-Id: Ib9542e478a57ad56d9fe2a0e97cb18a05d5d2535