bpftool: Fix missing closing parethesis for BTF_KIND_UNKN

In the btf_dumper_do_type function, the debug print statement for
BTF_KIND_UNKN was missing a closing parenthesis in the output format.
This patch adds the missing ')' to ensure proper formatting of the
dump output.

Signed-off-by: Zhang Chujun <[e-mail]>
Signed-off-by: Andrii Nakryiko <[e-mail]>
Link: https://lore.kernel.org/bpf/[e-mail]

tools/bpf/bpftool/btf_dumper.c

···
 	case BTF_KIND_DATASEC:
 		return btf_dumper_datasec(d, type_id, data);
 	default:
-		jsonw_printf(d->jw, "(unsupported-kind");
+		jsonw_printf(d->jw, "(unsupported-kind)");
 		return -EINVAL;
 	}
 }