perf intel-pt: Fix segfault in intel_pt_print_info() with uClibc

uClibc segfaulted because NULL was passed as the format to fprintf().

That happened because one of the format strings was missing and
intel_pt_print_info() didn't check that before calling fprintf().

Add the missing format string, and check format is not NULL before calling
fprintf().

Fixes: 11fa7cb8

 ("perf tools: Pass Intel PT information for decoding MTC and CYC")
Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221012082259.22394-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>