perf script: Remove some large stack allocations

perf script: Remove some large stack allocations

Some char buffers are stack allocated but in total they come to
24kb. Avoid Wstack-usage warnings by moving the arrays to being
dynamically allocated.

Signed-off-by: Ian Rogers <irogers@google.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>
Link: https://lore.kernel.org/r/20230527034324.2597593-3-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>