cpupower: Fix segfault due to incorrect getopt_long arugments

If a user calls 'cpupower set --perf-bias 15', the process will end with
a SIGSEGV in libc because cpupower-set passes a NULL optarg to the atoi
call.  This is because the getopt_long structure currently has all of
the options as having an optional_argument when they really have a
required argument.  We change the structure to use required_argument to
match the short options and it resolves the issue.

This fixes https://bugzilla.redhat.com/show_bug.cgi?id=1000439

Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Thomas Renninger <trenn@suse.de>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

tools/power/cpupower/utils/cpupower-set.c

@@ -18,9 +18,9 @@
 #include "helpers/bitmask.h"
 
 static struct option set_opts[] = {
-	{ .name = "perf-bias",	.has_arg = optional_argument,	.flag = NULL,	.val = 'b'},
-	{ .name = "sched-mc",	.has_arg = optional_argument,	.flag = NULL,	.val = 'm'},
-	{ .name = "sched-smt",	.has_arg = optional_argument,	.flag = NULL,	.val = 's'},
+	{ .name = "perf-bias",	.has_arg = required_argument,	.flag = NULL,	.val = 'b'},
+	{ .name = "sched-mc",	.has_arg = required_argument,	.flag = NULL,	.val = 'm'},
+	{ .name = "sched-smt",	.has_arg = required_argument,	.flag = NULL,	.val = 's'},
 	{ },
 };