libbpf: Update the comment to remove the reference to the deprecated interface bpf_program__load().

Commit be2f2d1(Deprecate bpf_program__load() API) marked
bpf_program__load() as deprecated starting with libbpf v0.6. And later
in commit 146bf81(remove most other deprecated high-level APIs)
actually removed the bpf_program__load() implementation and related old
high-level APIs.

This patch update the comment in bpf_program__set_attach_target() to
remove the reference to the deprecated interface bpf_program__load().

Signed-off-by: Jianyun Gao <[email protected]>

Author: Jianyun Gao

tools/lib/bpf/libbpf.c

@@ -13858,8 +13858,8 @@ int bpf_program__set_attach_target(struct bpf_program *prog,
 		return libbpf_err(-EINVAL);
 
 	if (attach_prog_fd && !attach_func_name) {
-		/* remember attach_prog_fd and let bpf_program__load() find
-		 * BTF ID during the program load
+		/* Store attach_prog_fd. The BTF ID will be resolved later during
+		 * the normal object/program load phase.
 		 */
 		prog->attach_prog_fd = attach_prog_fd;
 		return 0;