perf tests: Remove dependency on lscpu

This check can be done with uname which is more portable. At the same
time re-arrange it into a standard if statement so that it's more
readable.
Reviewed-by: Ian Rogers <irogers@google.com>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Spoorthy S <spoorts2@in.ibm.com>
Link: https://lore.kernel.org/r/20240410103458.813656-5-james.clark@arm.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/tests/shell/test_arm_callgraph_fp.sh

@@ -6,7 +6,9 @@ shelldir=$(dirname "$0")
 # shellcheck source=lib/perf_has_symbol.sh
 . "${shelldir}"/lib/perf_has_symbol.sh
 
-lscpu | grep -q "aarch64" || exit 2
+if [ "$(uname -m)" != "aarch64" ]; then
+	exit 2
+fi
 
 if perf version --build-options | grep HAVE_DWARF_UNWIND_SUPPORT | grep -q OFF
 then