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 byte(s) in 1 object(s) allocated from: #0 0x7f2953a7077b in interceptorstrdup ../../../../src/libsanitizer/asan/asaninterceptors.cpp:439 #1 0x556701d6fbbf in perfenvreadcpuid util/env.c:369 #2 0x556701d70589 in perfenvcpuid util/env.c:465 #3 0x55670204bba2 in x86isamdcpu arch/x86/util/env.c:14 #4 0x5567020487a2 in archpostevselconfig arch/x86/util/evsel.c:83 #5 0x556701d8f78b in evselconfig util/evsel.c:1366 #6 0x556701ef5872 in evlistconfig util/record.c:108 #7 0x556701cd6bcd in testPERFRECORD tests/perf-record.c:112 #8 0x556701cacd07 in runtest tests/builtin-test.c:236 #9 0x556701cacfac in testandprint tests/builtin-test.c:265 #10 0x556701cadddb in cmdtest tests/builtin-test.c:402 #11 0x556701caf2aa in cmdtest tests/builtin-test.c:559 #12 0x556701d3b557 in runbuiltin tools/perf/perf.c:323 #13 0x556701d3bac8 in handleinternalcommand tools/perf/perf.c:377 #14 0x556701d3be90 in runargv tools/perf/perf.c:421 #15 0x556701d3c3f8 in main tools/perf/perf.c:537 #16 0x7f2952a46189 in libcstartcallmain ../sysdeps/nptl/libcstartcallmain.h:58

SUMMARY: AddressSanitizer: 21 byte(s) leaked in 1 allocation(s).