CVE-2023-53793 perf tool x86: Fix perf_env memory leak

In the Linux kernel, the following vulnerability has been resolved: perf tool x86: Fix perfenv memory leak Found by leak sanitizer: ==1632594==ERROR: LeakSanitizer: detected memory leaks Direct leak of 21 bytes in 1 objects allocated from: 0 0x7f2953a7077b in interceptorstrdup...