pahole-flags.sh permission error reported in ubuntu_bpf test build

[Po-Hsu Lin]

This issue can be found on Jammy / F-5.15

While trying to build the ubuntu_bpf test, it will complain:
 Running 'make -C linux/tools/testing/selftests TARGETS=bpf SKIP_TARGETS= clean all'
 make: Entering directory '/home/azure/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests'
 make[1]: Entering directory '/home/azure/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf'
   CLEAN
 /bin/sh: 1: ./scripts/pahole-flags.sh: Permission denied
 /bin/sh: 1: ./scripts/pahole-flags.sh: Permission denied
   CLEAN eBPF_helpers-manpage
   CLEAN eBPF_syscall-manpage
 make[1]: Leaving directory '/home/azure/autotest/client/tmp/ubuntu_bpf/src/linux/tools/testing/selftests/bpf'
 make --no-builtin-rules ARCH=x86 -C ../../.. headers_install
 make[1]: Entering directory '/home/azure/autotest/client/tmp/ubuntu_bpf/src/linux'
 /bin/sh: 1: ./scripts/pahole-flags.sh: Permission denied
   HOSTCC scripts/basic/fixdep
 /bin/sh: 1: ./scripts/pahole-flags.sh: Permission denied

apw: fundamentally, after apt-get source; dpkg-source -x foo.dsc; you need to debian/rules clean the tree to use it

[Po-Hsu Lin (cypressyew)]

https://git.launchpad.net/~canonical-kernel-team/+git/autotest-client-tests/commit/?id=6d4527fd606133066527a2617dfd73c5bfd98b2d