[PATCH -next] x86: Fix unused variable 'msr_val' warning

[Xu Yihang]

Fixes the following W=1 kernel build warning(s):
arch/x86/hyperv/hv_spinlock.c:28:16: warning: variable ‘msr_val’ set but not 
used [-Wunused-but-set-variable]
  unsigned long msr_val;

Reported-by: Hulk Robot <hul...@huawei.com>
Signed-off-by: Xu Yihang <xuyih...@huawei.com>
---
 arch/x86/hyperv/hv_spinlock.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/hyperv/hv_spinlock.c b/arch/x86/hyperv/hv_spinlock.c
index f3270c1fc48c..67bc15c7752a 100644
--- a/arch/x86/hyperv/hv_spinlock.c
+++ b/arch/x86/hyperv/hv_spinlock.c
@@ -25,7 +25,7 @@ static void hv_qlock_kick(int cpu)
 
 static void hv_qlock_wait(u8 *byte, u8 val)
 {
-       unsigned long msr_val;
+       unsigned long msr_val __maybe_unused;
        unsigned long flags;
 
        if (in_nmi())
-- 
2.17.1