Error out on conflicting aa-exec parameters

If multiple -p/--profile or -n/--namespace parameters are given to
aa-exec, they are handled on a "last one wins" base.

This probably isn't expected behaviour, and erroring out in case of
conflicting parameters probably makes more sense.

binutils/aa_exec.c

@@ -131,9 +131,13 @@ static char **parse_args(int argc, char **argv)
 			usage(argv[0], false);
 			break;
 		case 'p':
+			if (opt_profile)
+				error("Multiple -p/--profile parameters given");
 			opt_profile = optarg;
 			break;
 		case 'n':
+			if (opt_namespace)
+				error("Multiple -n/--namespace parameters given");
 			opt_namespace = optarg;
 			break;
 		case 'i':