Fix clang-tidy found potential memory leak and unread value:
```
tools/perf/util/hisi-ptt.c:108:3: warning: Value stored to 'data_offset' is never read [clang-analyzer-deadcode.DeadStores]
                data_offset = 0;
                ^             ~
tools/perf/util/hisi-ptt.c:108:3: note: Value stored to 'data_offset' is never read
                data_offset = 0;
                ^             ~
tools/perf/util/hisi-ptt.c:112:12: warning: Potential leak of memory pointed to by 'data' [clang-analyzer-unix.Malloc]
                        return -errno;
                                ^
/usr/include/errno.h:38:18: note: expanded from macro 'errno'
                 ^
tools/perf/util/hisi-ptt.c:100:15: note: Memory is allocated
        void *data = malloc(size);
                     ^~~~~~~~~~~~
tools/perf/util/hisi-ptt.c:104:6: note: Assuming 'data' is non-null
        if (!data)
            ^~~~~
tools/perf/util/hisi-ptt.c:104:2: note: Taking false branch
        if (!data)
        ^
tools/perf/util/hisi-ptt.c:107:6: note: Assuming the condition is false
        if (perf_data__is_pipe(session->data)) {
            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/perf/util/hisi-ptt.c:107:2: note: Taking false branch
        if (perf_data__is_pipe(session->data)) {
        ^
tools/perf/util/hisi-ptt.c:111:7: note: Assuming the condition is true
                if (data_offset == -1)
                    ^~~~~~~~~~~~~~~~~
tools/perf/util/hisi-ptt.c:111:3: note: Taking true branch
                if (data_offset == -1)
                ^
tools/perf/util/hisi-ptt.c:112:12: note: Potential leak of memory pointed to by 'data'
                        return -errno;
                                ^
/usr/include/errno.h:38:18: note: expanded from macro 'errno'
```

Signed-off-by: Ian Rogers <irogers@google.com>
---
 tools/perf/util/hisi-ptt.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/tools/perf/util/hisi-ptt.c b/tools/perf/util/hisi-ptt.c
index 45b614bb73bf..ea297329c526 100644
--- a/tools/perf/util/hisi-ptt.c
+++ b/tools/perf/util/hisi-ptt.c
@@ -98,18 +98,18 @@ static int hisi_ptt_process_auxtrace_event(struct perf_session *session,
 	int fd = perf_data__fd(session->data);
 	int size = event->auxtrace.size;
 	void *data = malloc(size);
-	off_t data_offset;
 	int err;
 
 	if (!data)
 		return -errno;
 
-	if (perf_data__is_pipe(session->data)) {
-		data_offset = 0;
-	} else {
-		data_offset = lseek(fd, 0, SEEK_CUR);
-		if (data_offset == -1)
+	if (!perf_data__is_pipe(session->data)) {
+		off_t data_offset = lseek(fd, 0, SEEK_CUR);
+
+		if (data_offset == -1) {
+			free(data);
 			return -errno;
+		}
 	}
 
 	err = readn(fd, data, size);
-- 
2.42.0.515.g380fc7ccd1-goog