libbpf: Mark bpf_object__open_xattr() deprecated

Mark bpf_object__open_xattr() as deprecated, use
bpf_object__open_file() instead.

  [0] Closes: https://github.com/libbpf/libbpf/issues/287Signed-off-by: Christy Lee <christylee@fb.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220125010917.679975-1-christylee@fb.com

tools/lib/bpf/libbpf.c

@@ -9460,7 +9460,7 @@ static int bpf_prog_load_xattr2(const struct bpf_prog_load_attr *attr,
 	open_attr.file = attr->file;
 	open_attr.prog_type = attr->prog_type;
 
-	obj = bpf_object__open_xattr(&open_attr);
+	obj = __bpf_object__open_xattr(&open_attr, 0);
 	err = libbpf_get_error(obj);
 	if (err)
 		return libbpf_err(-ENOENT);

tools/lib/bpf/libbpf.h

@@ -184,6 +184,7 @@ LIBBPF_DEPRECATED_SINCE(0, 8, "use bpf_object__open_mem() instead")
 LIBBPF_API struct bpf_object *
 bpf_object__open_buffer(const void *obj_buf, size_t obj_buf_sz,
 			const char *name);
+LIBBPF_DEPRECATED_SINCE(0, 7, "use bpf_object__open_file() instead")
 LIBBPF_API struct bpf_object *
 bpf_object__open_xattr(struct bpf_object_open_attr *attr);