libbpf: Name changing for btf_get_from_id

s/btf_get_from_id/btf__get_from_id/ to restore the API naming convention.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index cbd3080..3850f8d 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -713,7 +713,7 @@ static int do_dump(int argc, char **argv)
 
 	prev_key = NULL;
 
-	err = btf_get_from_id(info.btf_id, &btf);
+	err = btf__get_from_id(info.btf_id, &btf);
 	if (err) {
 		p_err("failed to get btf");
 		goto exit_free;
@@ -857,7 +857,7 @@ static int do_lookup(int argc, char **argv)
 	}
 
 	/* here means bpf_map_lookup_elem() succeeded */
-	err = btf_get_from_id(info.btf_id, &btf);
+	err = btf__get_from_id(info.btf_id, &btf);
 	if (err) {
 		p_err("failed to get btf");
 		goto exit_free;