libbpf: Fix type compatibility check copy-paste error

Fix copy-paste error in types compatibility check. Local type is accidentally
used instead of target type for the very first type check strictness check.
This can result in potentially less strict candidate comparison. Fix the
error.

Fixes: 3fc32f4 ("libbpf: Implement type-based CO-RE relocations support")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200821225653.2180782-1-andriin@fb.com

tools/lib/bpf/libbpf.c

@@ -4708,7 +4708,7 @@ static int bpf_core_types_are_compat(const struct btf *local_btf, __u32 local_id
 
 	/* caller made sure that names match (ignoring flavor suffix) */
 	local_type = btf__type_by_id(local_btf, local_id);
-	targ_type = btf__type_by_id(local_btf, local_id);
+	targ_type = btf__type_by_id(targ_btf, targ_id);
 	if (btf_kind(local_type) != btf_kind(targ_type))
 		return 0;