[PATCH] kernel/watchdog: fix warning -Wunused-variable for watchdog_allowed_mask in ppc64

In ppc64 config if `CONFIG_SOFTLOCKUP_DETECTOR` is not set then it
warns for unused declaration of `watchdog_allowed_mask` while building,
move the declaration inside ifdef later in the code.

kernel/watchdog.c:47:23: warning: ‘watchdog_allowed_mask’ defined but not used [-Wunused-variable]
 static struct cpumask watchdog_allowed_mask __read_mostly;

Signed-off-by: Balamuruhan S <redacted>
---
 kernel/watchdog.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 5abb5b22ad13..33c9b8a3d51b 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c

@@ -44,7 +44,6 @@ int __read_mostly soft_watchdog_user_enabled = 1;
 int __read_mostly watchdog_thresh = 10;
 static int __read_mostly nmi_watchdog_available;
 
-static struct cpumask watchdog_allowed_mask __read_mostly;
 
 struct cpumask watchdog_cpumask __read_mostly;
 unsigned long *watchdog_cpumask_bits = cpumask_bits(&watchdog_cpumask);

@@ -166,6 +165,7 @@ int __read_mostly sysctl_softlockup_all_cpu_backtrace;
 unsigned int __read_mostly softlockup_panic =
 			CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE;
 
+static struct cpumask watchdog_allowed_mask __read_mostly;