trace_buffer: fix debug log statement (wrong var name) am: ae9673f68e am: 991acb52b2
trace_buffer: fix debug log statement (wrong var name) am: ae9673f68e
am: 991acb52b2

Change-Id: Ieb63132d65a7abb0ddcfe4fb1c6acc6178c62d69

google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto,google/perfetto