Merge branch 'core_reloc fixes for s390'

Ilya Leoshkevich says:

====================

v2: https://lore.kernel.org/bpf/20211025131214.731972-1-iii@linux.ibm.com/
v2 -> v3: Split the fix from the cleanup (Daniel).

v1: https://lore.kernel.org/bpf/20211021234653.643302-1-iii@linux.ibm.com/
v1 -> v2: Drop bpf_core_calc_field_relo() restructuring, split the
          __BYTE_ORDER__ change (Andrii).

Hi,

this series fixes test failures in core_reloc on s390.

Patch 1 fixes an endianness bug with __BYTE_ORDER vs __BYTE_ORDER__.
Patches 2-5 make the rest of the code consistent in that respect.
Patch 6 fixes an endianness issue in test_core_reloc_mods.

Best regards,
Ilya
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Signed-off-by: Andrii Nakryiko <andrii@kernel.org>