libbpf: deprecate bpf_map__resize()

Deprecated bpf_map__resize() in favor of bpf_map__set_max_entries()
setter. In addition to having a surprising name (users often don't
realize that they need to use bpf_map__resize()), the name also implies
some magic way of resizing BPF map after it is created, which is clearly
not the case.

Another minor annoyance is that bpf_map__resize() disallows 0 value for
max_entries, which in some cases is totally acceptable (e.g., like for
BPF perf buf case to let libbpf auto-create one buffer per each
available CPU core).

  [0] Closes: https://github.com/libbpf/libbpf/issues/304Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220124194254.2051434-3-andrii@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/lib/bpf/libbpf.h

@@ -718,6 +718,7 @@ LIBBPF_API int bpf_map__set_type(struct bpf_map *map, enum bpf_map_type type);
 /* get/set map size (max_entries) */
 LIBBPF_API __u32 bpf_map__max_entries(const struct bpf_map *map);
 LIBBPF_API int bpf_map__set_max_entries(struct bpf_map *map, __u32 max_entries);
+LIBBPF_DEPRECATED_SINCE(0, 8, "use bpf_map__set_max_entries() instead")
 LIBBPF_API int bpf_map__resize(struct bpf_map *map, __u32 max_entries);
 /* get/set map flags */
 LIBBPF_API __u32 bpf_map__map_flags(const struct bpf_map *map);