perf hisi-ptt: Fix memory leak in lseek failure handling

perf hisi-ptt: Fix memory leak in lseek failure handling

In the previous code, there was a memory leak issue where the previously
allocated memory was not freed upon a failed lseek operation. This patch
addresses the problem by releasing the old memory before returning -errno
in case of a lseek failure. This ensures that memory is properly managed
and avoids potential memory leaks.

Signed-off-by: Kuan-Wei Chiu <visitorckw@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: yangyicong@hisilicon.com
Cc: jonathan.cameron@huawei.com
Link: https://lore.kernel.org/r/20230930072719.1267784-1-visitorckw@gmail.com
Signed-off-by: Namhyung Kim <namhyung@kernel.org>