libbpf: Fix typo in btf__dedup@LIBBPF_0.0.2 definition

The btf__dedup_deprecated name was misspelled in the definition of the
compat symbol for btf__dedup. This leads it to be missing from the
shared library.

This fixes it.

Fixes: 957d350a

 ("libbpf: Turn btf_dedup_opts into OPTS-based struct")
Signed-off-by: Vincent Minet <vincent@vincent-minet.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211210063112.80047-1-vincent@vincent-minet.net