perf tool x86: Fix perf_env 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 __interceptor_strdup ../../../../src/libsanitizer/asan/asan_interceptors.cpp:439
#1 0x556701d6fbbf in perf_env__read_cpuid util/env.c:369
#2 0x556701d70589 in perf_env__cpuid util/env.c:465
#3 0x55670204bba2 in x86__is_amd_cpu arch/x86/util/env.c:14
#4 0x5567020487a2 in arch__post_evsel_config arch/x86/util/evsel.c:83
#5 0x556701d8f78b in evsel__config util/evsel.c:1366
#6 0x556701ef5872 in evlist__config util/record.c:108
#7 0x556701cd6bcd in test__PERF_RECORD tests/perf-record.c:112
#8 0x556701cacd07 in run_test tests/builtin-test.c:236
#9 0x556701cacfac in test_and_print tests/builtin-test.c:265
#10 0x556701cadddb in __cmd_test tests/builtin-test.c:402
#11 0x556701caf2aa in cmd_test tests/builtin-test.c:559
#12 0x556701d3b557 in run_builtin tools/perf/perf.c:323
#13 0x556701d3bac8 in handle_internal_command tools/perf/perf.c:377
#14 0x556701d3be90 in run_argv tools/perf/perf.c:421
#15 0x556701d3c3f8 in main tools/perf/perf.c:537
#16 0x7f2952a46189 in __libc_start_call_main ../sysdeps/nptl/libc_start_call_main.h:58

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

Fixes: f7b58cbdb3ff36eb ("perf mem/c2c: Add load store event mappings for AMD")
Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Ravi Bangoria <ravi.bangoria@amd.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20230613235416.1650755-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf tool x86: Consolidate is_amd check into single function

There are multiple places where x86 specific code determines AMD vs
Intel arch and acts based on that. Consolidate those checks into a
single function.

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ali Saidi <alisaidi@amazon.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Link: https://lore.kernel.org/r/20230613095506.547-3-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>