objtool: Fix seg fault caused by missing parameter

Fix a seg fault when no parameter is provided to 'objtool orc'.

Signed-off-by: Simon Ser <[e-mail]>
Signed-off-by: Josh Poimboeuf <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

tools/objtool/builtin-orc.c

···
 	const char *objname;
 
 	argc--; argv++;
+	if (argc <= 0)
+		usage_with_options(orc_usage, check_options);
+
 	if (!strncmp(argv[0], "gen", 3)) {
 		argc = parse_options(argc, argv, check_options, orc_usage, 0);
 		if (argc != 1)
···
 		objname = argv[0];
 
 		return check(objname, no_fp, no_unreachable, true);
-
 	}
 
 	if (!strcmp(argv[0], "dump")) {