kexec: fix compilation warning on xchg(&kexec_lock, 0) in kernel_kexec()

kernel/kexec.c: In function 'kernel_kexec':
kernel/kexec.c:1506: warning: value computed is not used

Signed-off-by: Huang Ying <ying.huang@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/kexec.c b/kernel/kexec.c
index c8a4370..cf3797b 100644 (file)
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1503,7 +1503,8 @@ int kernel_kexec(void)
        }
 
  Unlock:
-       xchg(&kexec_lock, 0);
+       if (!xchg(&kexec_lock, 0))
+               BUG();
 
        return error;
 }