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>

networking/libiproute/ip_parse_common_args.c

@@ -67,7 +67,7 @@ char** FAST_FUNC ip_parse_common_args(char **argv)
 				bb_show_usage();
 			arg = index_in_strings(families, *argv);
 			if (arg < 0)
-				invarg(*argv, "protocol family");
+				invarg_1_to_2(*argv, "family");
 			/* now arg == 0, 1 or 2 */
 		} else {
 			arg -= ARG_IPv4;