iproute2: Mention the 'up' argument in documentation

Both ip-link and ip-address support the 'up' argument, however this
isn't documented in neither their help outputs or ip-address' manpage.
This patch fixes that.

Signed-off-by: Petr Šabata <contyk@redhat.com>
Reported-by: Jiří Popelka <jpopelka@redhat.com>
diff --git a/ip/ipaddress.c b/ip/ipaddress.c
index fdd2a74..3c08ace 100644
--- a/ip/ipaddress.c
+++ b/ip/ipaddress.c
@@ -71,7 +71,7 @@
 	fprintf(stderr, "                                                      [ CONFFLAG-LIST ]\n");
 	fprintf(stderr, "       ip addr del IFADDR dev STRING\n");
 	fprintf(stderr, "       ip addr {show|save|flush} [ dev STRING ] [ scope SCOPE-ID ]\n");
-	fprintf(stderr, "                            [ to PREFIX ] [ FLAG-LIST ] [ label PATTERN ]\n");
+	fprintf(stderr, "                            [ to PREFIX ] [ FLAG-LIST ] [ label PATTERN ] [up]\n");
 	fprintf(stderr, "       ip addr {showdump|restore}\n");
 	fprintf(stderr, "IFADDR := PREFIX | ADDR peer PREFIX\n");
 	fprintf(stderr, "          [ broadcast ADDR ] [ anycast ADDR ]\n");