perf tools: Fix segfault in cpu_cache_level__read()

[ Upstream commit 0216234c2eed1367a318daeb9f4a97d8217412a0 ]

We release wrong pointer on error path in cpu_cache_level__read
function, leading to segfault:

  (gdb) r record ls
  Starting program: /root/perf/tools/perf/perf record ls
  ...
  [ perf record: Woken up 1 times to write data ]
  double free or corruption (out)

  Thread 1 "perf" received signal SIGABRT, Aborted.
  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  (gdb) bt
  #0  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  150balbes#1  0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6
  150balbes#2  0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6
  150balbes#3  0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6
  150balbes#4  0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6
  150balbes#5  0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc..
  150balbes#6  0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac..
  150balbes#7  0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz..
  ...

Releasing the proper pointer.

Fixes: 720e98b ("perf tools: Add perf data cache feature")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org: # v4.6+
Link: http://lore.kernel.org/lkml/20190912105235.10689-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

tools/perf/util/header.c

@@ -1114,7 +1114,7 @@ static int cpu_cache_level__read(struct cpu_cache_level *cache, u32 cpu, u16 lev
 
 	scnprintf(file, PATH_MAX, "%s/shared_cpu_list", path);
 	if (sysfs__read_str(file, &cache->map, &len)) {
-		free(cache->map);
+		free(cache->size);
 		free(cache->type);
 		return -1;
 	}