libbpf: fix typos in Makefile

Capitalize ABI (acronym) and fix spelling of "destination".

Fixes: 70681949 ("libbpf: Improve usability of libbpf Makefile")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org
Cc: Xin Liu <liuxin350@huawei.com>
Link: https://lore.kernel.org/r/20230722065236.17010-1-rdunlap@infradead.org


Signed-off-by: Alexei Starovoitov <ast@kernel.org>