libiproute: rename invarg(a,b) to invarg_1_to_2(a,b)

invarg(a,b) - "invalid argument", but how a and b enter the message?

invarg_1_to_2(a,b) is somewhat easier to read: "invalid argument 'a' to 'b'"

Audit of usage revealed a number of bad uses, with too long messages.

   text	   data	    bss	    dec	    hex	filename
 938848	    932	  17448	 957228	  e9b2c	busybox_old
 938788	    932	  17448	 957168	  e9af0	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
diff --git a/networking/libiproute/iprule.c b/networking/libiproute/iprule.c
index 774a3e2..c3b2109 100644
--- a/networking/libiproute/iprule.c
+++ b/networking/libiproute/iprule.c
@@ -214,7 +214,7 @@
 	while (*argv) {
 		key = index_in_substrings(keywords, *argv) + 1;
 		if (key == 0) /* no match found in keywords array, bail out. */
-			invarg(*argv, applet_name);
+			invarg_1_to_2(*argv, applet_name);
 		if (key == ARG_from) {
 			inet_prefix dst;
 			NEXT_ARG();
@@ -239,7 +239,7 @@
 			uint32_t tos;
 			NEXT_ARG();
 			if (rtnl_dsfield_a2n(&tos, *argv))
-				invarg(*argv, "TOS");
+				invarg_1_to_2(*argv, "TOS");
 			req.r.rtm_tos = tos;
 		} else if (key == ARG_fwmark) {
 			uint32_t fwmark;
@@ -250,7 +250,7 @@
 			uint32_t realm;
 			NEXT_ARG();
 			if (get_rt_realms(&realm, *argv))
-				invarg(*argv, "realms");
+				invarg_1_to_2(*argv, "realms");
 			addattr32(&req.n, sizeof(req), RTA_FLOW, realm);
 		} else if (key == ARG_table ||
 			   key == ARG_lookup
@@ -258,7 +258,7 @@
 			uint32_t tid;
 			NEXT_ARG();
 			if (rtnl_rttable_a2n(&tid, *argv))
-				invarg(*argv, "table ID");
+				invarg_1_to_2(*argv, "table ID");
 			req.r.rtm_table = tid;
 			table_ok = 1;
 		} else if (key == ARG_dev ||
@@ -281,7 +281,7 @@
 			if (key == ARG_help)
 				bb_show_usage();
 			if (rtnl_rtntype_a2n(&type, *argv))
-				invarg(*argv, "type");
+				invarg_1_to_2(*argv, "type");
 			req.r.rtm_type = type;
 		}
 		argv++;
@@ -309,7 +309,7 @@
 	if (*argv) {
 		int cmd = index_in_substrings(ip_rule_commands, *argv);
 		if (cmd < 0)
-			invarg(*argv, applet_name);
+			invarg_1_to_2(*argv, applet_name);
 		argv++;
 		if (cmd < 2)
 			return iprule_modify((cmd == 0) ? RTM_NEWRULE : RTM_DELRULE, argv);