Modify usage() to take a process exit_code parameter and directly call
exit() after printing the usage string.  This simplifies the callers'
code paths.

Remove the manual "Invalid option" error message at option parsing,
since getopt_long(3) already prints sensible error messages by default.

Signed-off-by: Ahmed S. Darwish <darwi@linutronix.de>
---
 tools/arch/x86/kcpuid/kcpuid.c | 21 ++++++++-------------
 1 file changed, 8 insertions(+), 13 deletions(-)

diff --git a/tools/arch/x86/kcpuid/kcpuid.c b/tools/arch/x86/kcpuid/kcpuid.c
index ac8fdfdc4844..c0f2eae0d694 100644
--- a/tools/arch/x86/kcpuid/kcpuid.c
+++ b/tools/arch/x86/kcpuid/kcpuid.c
@@ -11,6 +11,7 @@
 
 #define ARRAY_SIZE(x)	(sizeof(x) / sizeof((x)[0]))
 #define min(a, b)	(((a) < (b)) ? (a) : (b))
+#define __noreturn	__attribute__((__noreturn__))
 
 typedef unsigned int u32;
 typedef unsigned long long u64;
@@ -608,9 +609,9 @@ static void setup_platform_cpuid(void)
 	leafs_ext = setup_cpuid_range(0x80000000);
 }
 
-static void usage(void)
+static void __noreturn usage(int exit_code)
 {
-	pr_err("kcpuid [-abdfhr] [-l leaf] [-s subleaf]\n"
+	pr_err_exit(exit_code, "kcpuid [-abdfhr] [-l leaf] [-s subleaf]\n"
 		"\t-a|--all             Show both bit flags and complex bit fields info\n"
 		"\t-b|--bitflags        Show boolean flags only\n"
 		"\t-d|--detail          Show details of the flag/fields (default)\n"
@@ -634,7 +635,7 @@ static struct option opts[] = {
 	{ NULL, 0, NULL, 0 }
 };
 
-static int parse_options(int argc, char *argv[])
+static void parse_options(int argc, char *argv[])
 {
 	int c;
 
@@ -654,9 +655,7 @@ static int parse_options(int argc, char *argv[])
 			user_csv = optarg;
 			break;
 		case 'h':
-			usage();
-			exit(1);
-			break;
+			usage(EXIT_SUCCESS);
 		case 'l':
 			/* main leaf */
 			user_index = strtoul(optarg, NULL, 0);
@@ -669,11 +668,8 @@ static int parse_options(int argc, char *argv[])
 			user_sub = strtoul(optarg, NULL, 0);
 			break;
 		default:
-			pr_err("%s: Invalid option '%c'\n", argv[0], optopt);
-			return -1;
-	}
-
-	return 0;
+			usage(EXIT_FAILURE);
+		}
 }
 
 /*
@@ -686,8 +682,7 @@ static int parse_options(int argc, char *argv[])
  */
 int main(int argc, char *argv[])
 {
-	if (parse_options(argc, argv))
-		return -1;
+	parse_options(argc, argv);
 
 	/* Setup the cpuid leafs of current platform */
 	setup_platform_cpuid();
-- 
2.46.2