Comment # 9 on bug 1229450 from Jiri Slaby

FWIW:
  -j, --jobs[=NR_JOBS]       run N jobs in parallel [default to number of
                             online processors + 10%]

But how many? The build logs show -smp 12 for i586 and 4 for arm and they still
fail.

12 gives 13, 4 gives 4, 160 gives 176.

If I use -j32 on my machine, it indeed fails. So I updated the docker image
accordingly.

Maybe we should just use -j1 (or no -j at all) on 32bit as with pahole < 122.
See scripts/Makefile.btf:
 pahole-flags-$(call test-ge, $(pahole-ver), 122)        += -j

(Or disable btf on 32bit completely.)