During cross-compilation, it was discovered that LDFLAGS and
LDLIBS were not being used while building binaries, leading
to defaults which were not necessarily correct.

OpenEmbedded reported this kind of problem:

  ERROR: QA Issue: No GNU_HASH in the ELF binary [...], didn't pass LDFLAGS?
Signed-off-by: NDaniel Díaz <daniel.diaz@linaro.org>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
Acked-by: NAndrii Nakryiko <andriin@fb.com>
Acked-by: NJohn Fastabend <john.fastabend@gmail.com>