Free tracing_data structure in tracing_data_get() error paths.

Fixes the following coverity complaint:

  Error: RESOURCE_LEAK (CWE-772):
  leaked_storage: Variable "tdata" going out of scope leaks the storage
Signed-off-by: Sanskriti Sharma <sansharm@redhat.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Cc: Joe Lawrence <joe.lawrence@redhat.com>
Link: http://lkml.kernel.org/r/1538490554-8161-3-git-send-email-sansharm@redhat.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>