perf test session topology: Fix data path

Commit 2d4f2799 ("perf data: Add global path holder") missed path
conversion in tests/topology.c, causing the "Session topology" testcase
to "hang" (waits forever for input from stdin) when doing "ssh $VM perf
test".

Can be reproduced by running "cat | perf test topo", and crashed by
replacing cat with true:

  $ true | perf test -v topo
  40: Session topology                                      :
  --- start ---
  test child forked, pid 3638
  templ file: /tmp/perf-test-QPvAch
  incompatible file format
  incompatible file format (rerun with -v to learn more)
  free(): invalid pointer
  test child interrupted
  ---- end ----
  Session topology: FAILED!

Committer testing:

Reproduced the above result before the patch and after it is back
working:

  # true | perf test -v topo
  41: Session topology                                      :
  --- start ---
  test child forked, pid 19374
  templ file: /tmp/perf-test-YOTEQg
  CPU 0, core 0, socket 0
  CPU 1, core 1, socket 0
  CPU 2, core 2, socket 0
  CPU 3, core 3, socket 0
  CPU 4, core 0, socket 0
  CPU 5, core 1, socket 0
  CPU 6, core 2, socket 0
  CPU 7, core 3, socket 0
  test child finished with 0
  ---- end ----
  Session topology: Ok
  #

Fixes: 2d4f2799 ("perf data: Add global path holder")
Signed-off-by: Tommi Rantala <tommi.t.rantala@nokia.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mamatha Inamdar <mamatha4@linux.vnet.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200423115341.562782-1-tommi.t.rantala@nokia.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>