add help command to bonding master

Signed-off-by: Jiri Pirko <jiri@resnulli.us>
diff --git a/ip/iplink_bond.c b/ip/iplink_bond.c
index b5c511e..0a1ed03 100644
--- a/ip/iplink_bond.c
+++ b/ip/iplink_bond.c
@@ -339,6 +339,9 @@
 			}
 			ad_select = get_index(ad_select_tbl, *argv);
 			addattr8(n, 1024, IFLA_BOND_AD_SELECT, ad_select);
+		} else if (matches(*argv, "help") == 0) {
+			explain();
+			return -1;
 		} else {
 			fprintf(stderr, "bond: unknown command \"%s\"?\n", *argv);
 			explain();