Merge branch 'RISC-V selftest/bpf fixes'

Björn Töpel says:

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

This series contain some fixes for selftests/bpf when building/running
on a RISC-V host. Details can be found in each individual commit.

v2:
  Makefile cosmetics. (Andrii)
  Simplified unpriv check and added comment. (Andrii)
====================

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>