selftests/bpf: Adjust bpf_map layout in verifier_map_ptr

With write-only excl member removed from struct bpf_map, ops moves
to offset 32 and inner_map_meta to offset 40. Update the expected
verifier message for the former and retarget the latter at the sha
byte array, so the beyond-member-end rejection path stays covered:

  # LDLIBS=-static PKG_CONFIG='pkg-config --static' ./vmtest.sh -- ./test_progs -t verifier_map_ptr
  [...]
  #619/5   verifier_map_ptr/bpf_map_ptr: read non-existent field rejected:OK
  #619/6   verifier_map_ptr/bpf_map_ptr: read non-existent field rejected @unpriv:OK
  #619/7   verifier_map_ptr/bpf_map_ptr: read beyond sha field rejected:OK
  #619/8   verifier_map_ptr/bpf_map_ptr: read beyond sha field rejected @unpriv:OK
  #619/9   verifier_map_ptr/bpf_map_ptr: read ops field accepted:OK
  #619/10  verifier_map_ptr/bpf_map_ptr: read ops field accepted @unpriv:OK
  [...]
  #620     verifier_map_ptr_mixing:OK
  Summary: 2/20 PASSED, 0 SKIPPED, 0 FAILED

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20260708075343.358712-7-daniel@iogearbox.net
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>