perf tests code-reading: Handle change in objdump output from binutils >= 2.41 on riscv

After binutils commit e43d876 which was first included in binutils 2.41,
riscv no longer supports dumping in the middle of instructions.

Increase the objdump window by 2-bytes to ensure that any instruction
that sits on the boundary of the specified stop-address is not cut in
half.

Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-riscv@lists.infradead.org
Link: https://lore.kernel.org/r/20241219-perf_fix_riscv_obj_reading-v3-1-a7d644dcfa50@rivosinc.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>