libbpf: Fix memory leak in strset

Free struct strset itself, not just its internal parts.

Fixes: 90d76d3ececc ("libbpf: Extract internal set-of-strings datastructure APIs")
Signed-off-by: Andrii Nakryiko <[e-mail]>
Signed-off-by: Daniel Borkmann <[e-mail]>
Acked-by: Martin KaFai Lau <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/lib/bpf/strset.c

···
 
 	hashmap__free(set->strs_hash);
 	free(set->strs_data);
+	free(set);
 }
 
 size_t strset__data_size(const struct strset *set)