x86: hide cond_syscall behind __KERNEL__

This brings x86_64 into line with all other architectures by only defining
cond_syscall() when __KERNEL__ is defined.

[ tglx: arch/x86 adaptation ]
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

include/asm-x86/unistd_64.h

@@ -676,6 +676,7 @@ asmlinkage long sys_rt_sigaction(int sig,
 #endif	/* __KERNEL__ */
 #endif	/* __NO_STUBS */
 
+#ifdef __KERNEL__
 /*
  * "Conditional" syscalls
  *
@@ -683,5 +684,6 @@ asmlinkage long sys_rt_sigaction(int sig,
  * but it doesn't work on all toolchains, so we just do it by hand
  */
 #define cond_syscall(x) asm(".weak\t" #x "\n\t.set\t" #x ",sys_ni_syscall")
+#endif	/* __KERNEL__ */
 
 #endif /* _ASM_X86_64_UNISTD_H_ */